1 of 40 REV: 070505
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any devic
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FEATURES
§ 80C32-Compatible
8051 Pin and Instruction Set Compatible
Four 8-Bit I/O Ports
Three 16-Bit Timer/Counters
256 Bytes Scratchpad RAM
Addresses 64kB ROM and 64kB RAM
§ High-Speed Architecture
4 Clocks/Machine Cycle (8032 = 12)
DC to 33MHz (DS80C320)
DC to 18MHz (DS80C323)
Single-Cycle Instruction in 121ns
Uses Less Power for Equivalent Work
Dual Data Pointer
Optional Variable Length MOVX to Access
Fast/Slow RAM/Peripherals
§ High-Integration Controller Includes:
Power-Fail Reset
Programmable Watchdog Timer
Early Warning Power-Fail Interrupt
§ Two Full-Duplex Hardware Serial Ports
§ 13 Total Interrupt Sources with Six
External
§ Available in 40-Pin DIP, 44-Pin PLCC, and
44-Pin TQFP
The High-Speed Microcontroller User’s Guide must be
used in conjunction with this data sheet. Download it
at: www.maxim-ic.com/microcontrollers.
Data sheets contain pin descriptions, feature
overviews, and electrical specifications, whereas the
user’s guide contains detailed information about
device features and operation.
PIN CONFIGURATIONS
DS80C320/DS80C323
High-Speed/Low-Power Microcontrollers
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DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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DETAILED DESCRIPTION
The DS80C320/DS80C323 are fast 80C31/80C32-compatible microcontrollers. Wasted clock and
memory cycles have been removed using a redesigned processor core. As a result, every 8051 instruction
is executed between 1.5 and 3 times faster than the original for the same crystal speed. Typical
applications see a speed improvement of 2.5 times using the same code and same crystal. The DS80C320
offers a maximum crystal rate of 33MHz, resulting in apparent execution speeds of 82.5MHz
(approximately 2.5X).
The DS80C320/DS80C323 are pin compatible with all three packages of the standard 80C32 and offer
the same timer/counters, serial port, and I/O ports. In short, the devices are extremely familiar to 8051
users, but provide the speed of a 16-bit processor.
The DS80C320 provides several extras in addition to greater speed. These include a second full hardware
serial port, seven additional interrupts, programmable watchdog timer, power-fail interrupt and reset. The
device also provides dual data pointers (DPTRs) to speed block data memory moves. It can also adjust the
speed of off-chip data memory access to between two and nine machine cycles for flexibility in selecting
memory and peripherals.
The DS80C320 operating voltage ranges from 4.25V to 5.5V, making it ideal as a high-performance
upgrade to existing 5V systems. For applications in which power consumption is critical, the DS80C323
offers the same feature set as the DS80C320, but with 2.7V to 5.5V operation.
Designers must have two documents to fully use all the features of this device: this data sheet and the
High-Speed Microcontroller User’s Guide, available on our website at
www.maxim-ic.com/microcontrollers. Data sheets contain pin descriptions, feature overviews, and
electrical specifications, whereas our user’s guides contain detailed information about device features and
operation.
ORDERING INFORMATION
PART Pb-FREE/RoHS-
COMPLIANT TEMP RANGE MAX CLOCK
SPEED (MHz) PIN-PACKAGE
DS80C320-MCG DS80C320+MCG 0°C to +70°C 25 40 Plastic DIP
DS80C320-QCG DS80C320+QCG 0°C to +70°C 25 44 PLCC
DS80C320-ECG DS80C320+ECG 0°C to +70°C 25 44 TQFP
DS80C320-MNG DS80C320+MNG -40°C to +85°C 25 40 Plastic DIP
DS80C320-QNG DS80C320+QNG -40°C to +85°C 25 44 PLCC
DS80C320-ENG DS80C320+ENG -40°C to +85°C 25 44 TQFP
DS80C320-MCL DS80C320+MCL 0°C to +70°C 33 40 Plastic DIP
DS80C320-QCL DS80C320+QCL 0°C to +70°C 33 44 PLCC
DS80C320-ECL DS80C320+ECL 0°C to +70°C 33 44 TQFP
DS80C320-MNL DS80C320+MNL -40°C to +85°C 33 40 Plastic DIP
DS80C320-QNL DS80C320+QNL -40°C to +85°C 33 44 PLCC
DS80C320-ENL DS80C320+ENL -40°C to +85°C 33 44 TQFP
DS80C323-MCD DS80C323+MCD 0°C to +70°C 18 40 Plastic DIP
DS80C323-QCD DS80C323+QCD 0°C to +70°C 18 44 PLCC
DS80C323-ECD DS80C323+ECD 0°C to +70°C 18 44 TQFP
DS80C323-MND DS80C323+MND -40°C to +85°C 18 40 Plastic DIP
DS80C323-QND DS80C323+QND -40°C to +85°C 18 44 PLCC
DS80C323-END DS80C323+END -40°C to +85°C 18 44 TQFP
+ Denotes a Pb-free/RoHS-compliant device.
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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Figure 1. Block Diagram
PIN DESCRIPTION
PIN
DIP PLCC
TQFP
NAME FUNCTION
40 44 38 VCC +5V (+3V for DS80C323)
20 22, 23
16, 17 GND Digital Circuit Ground
9 10 4 RST
Reset Input. The RST input pin contains a Schmitt voltage input to
recognize external active-high reset inputs. The pin also employs an
internal pulldown resistor to allow for a combination of wired OR
external reset sources. An RC is not required for power-up, as the device
provides this function internally.
18 20 14 XTAL2
19 21 15 XTAL1
Crystal Oscillator Pins. XTAL1 and XTAL2 provide support for
parallel-resonant, AT-cut crystals. XTAL1 acts also as an input in the
event that an external clock source is used in place of a crystal. XTAL2
serves as the output of the crystal amplifier.
29 32 26 PSEN
Program Store-Enable Output, Active Low. This signal is commonly
connected to external ROM memory as a chip enable. PSEN provides an
active-low pulse width of 2.25 XTAL1 cycles with a period of four
XTAL1 cycles. PSEN is driven high when data memory (RAM) is being
accessed through the bus and during a reset condition.
DS80C320/
DS80C323
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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PIN DESCRIPTION (continued)
PIN
DIP PLCC TQFP NAME FUNCTION
30 33 27 ALE
Address Latch-Enable Output. This pin functions as a clock to latch
the external address LSB from the multiplexed address/data bus. This
signal is commonly connected to the latch enable of an external 373
family transparent latch. ALE has a pulse width of 1.5 XTAL1 cycles
and a period of four XTAL1 cycles. ALE is forced high when the
device is in a reset condition.
39 43 37 AD0
38 42 36 AD1
37 41 35 AD2
36 40 34 AD3
35 39 33 AD4
34 38 32 AD5
33 37 31 AD6
32 36 30 AD7
Port 0, Input/Output. Port 0 is the multiplexed address/data bus.
During the time when ALE is high, the LSB of a memory address is
presented. When ALE falls, the port transitions to a bi-directional data
bus. This bus is used to read external ROM and read/write external
RAM memory or peripherals. The Port 0 has no true port latch and
cannot be written directly by software. The reset condition of Port 0 is
high. No pullup resistors are needed.
Port 1, I/O. Port 1 functions as both an 8-bit, bidirectional I/O port and
an alternate functional interface for Timer 2 I/O, new External
Interrupts, and new Serial Port 1. The reset condition of Port 1 is with
all bits at logic 1. In this state, a weak pullup holds the port high. This
condition also serves as an input mode, since any external circuit that
writes to the port will overcome the weak pullup. When software writes
a 0 to any port pin, the device will activate a strong pulldown that
remains on until either a 1 is written or a reset occurs. Writing a 1 after
the port has been at 0 will cause a strong transition driver to turn on,
followed by a weaker sustaining pullup. Once the momentary strong
driver turns off, the port once again becomes the output high (and
input) state. The alternate modes of Port 1 are outlined as follows:
PIN
DIP PLCC TQFP PORT ALTERNATE FUNCTION
1 2 40
P1.0 T2
External I/O for
Timer/Counter 2
2 3 41
P1.1 T2EX
Timer/Counter 2
Capture/Reload Trigger
3 4 42
P1.2 RXD1 Serial Port 1 Input
4 5 43
P1.3 TXD1 Serial Port 1 Output
5 6 44
P1.4 INT2
External Interrupt 2
(Positive-Edge Detect)
6 7 1
P1.5 INT3 External Interrupt 3
(Negative-Edge Detect)
7 8 2
P1.6 INT4
External Interrupt 4
(Positive-Edge Detect)
1–8 2–9 40–44,
1–3 P1.0–P1.7
8 9 3
P1.7 INT5 External Interrupt 5
(Negative-Edge Detect)
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PIN DESCRIPTION (continued)
PIN
DIP PLCC TQFP NAME FUNCTION
21 24 18 A8 (P2.0)
22 25 19 A9 (P2.1)
23 26 20 A10 (P2.2)
24 27 21 A11 (P2.3)
25 28 22 A12 (P2.4)
26 29 23 A13 (P2.5)
27 30 24 A14 (P2.6)
28 31 25 A15 (P2.7)
Port 2, Output. Port 2 serves as the MSB for external addressing.
P2.7 is A15 and P2.0 is A8. The device will automatically place the
MSB of an address on P2 for external ROM and RAM access.
Although Port 2 can be accessed like an ordinary I/O port, the value
stored on the Port 2 latch will never be seen on the pins (due to
memory access). Therefore, writing to Port 2 in software is only
useful for the instructions MOVX A, @Ri or MOVX @Ri, A. These
instructions use the Port 2 internal latch to supply the external address
MSB. In this case, the Port 2 latch value will be supplied as the
address information.
Port 3, Input/Output. Port 3 functions as both an 8-bit, bidirectional
I/O port and an alternate functional interface for External Interrupts,
Serial Port 0, Timer 0 & 1 Inputs, RD and WR strobes. The reset
condition of Port 3 is with all bits at logic 1. In this state, a weak
pullup holds the port high. This condition also serves as an input
mode, since any external circuit that writes to the port will overcome
the weak pullup. When software writes a 0 to any port pin, the device
will activate a strong pulldown that remains on until either a 1 is
written or a reset occurs. Writing a 1 after the port has been at 0 will
cause a strong transition driver to turn on, followed by a weaker
sustaining pullup. Once the momentary strong driver turns off, the
port once again becomes both the output high and input state. The
alternate modes of Port 3 are outlined below:
PIN
DIP PLCC TQFP PORT ALTERNATE MODE
10 11 5 P3.0 RXD0 Serial Port 0 Input
11 13 7 P3.1 TXD0 Serial Port 0 Output
12 14 8 P3.2 INT0 External Interrupt 0
13 15 9 P3.3 INT1 External Interrupt 1
14 16 10 P3.4 T0 Timer 0 External Input
15 17 11 P3.5 T1 Timer 1 External Input
16 18 12 P3.6 WR External Data Memory Write
Strobe
10–17 11, 13–
19 5, 7–13 P3.0–P3.7
17 19 13 P3.7 RD External Data Memory Read
Strobe
31 35 29 EA External Access, Active-Low Input. This pin must be connected to
ground for proper operation.
— 12, 34,
1*
6, 28,
39* N.C.
No Connection (Reserved). These pins should not be connected.
They are reserved for use with future devices in this family.
*These pins are reserved for additional ground pins on future products.
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80C32 COMPATIBILITY
The DS80C320/DS80C323 are CMOS 80C32-compatible microcontrollers designed for high
performance. In most cases, the devices will drop into an existing 80C32 design to significantly improve
the operation. Every effort has been made to keep the devices familiar to 8032 users, yet they have many
new features. In general, software written for existing 80C32-based systems will work on the DS80C320
and DS80C323. The exception is critical timing, because the high-speed microcontroller performs its
instructions much faster than the original. It may be necessary to use memories with faster access times if
the same crystal frequency is used.
Application Note 57: DS80C320 Memory Interface Timing is a useful tool to help the embedded system
designer select the proper memories for her or his application.
The DS80C320/DS80C323 run the standard 8051 instruction set and is pin compatible with an 80C32 in
any of three standard packages. They also provide the same timer/counter resources, full-duplex serial
port, 256 bytes of scratchpad RAM, and I/O ports as the standard 80C32. Timers will default to a 12
clock-per-cycle operation to keep timing compatible with original 8051 systems. However, they can be
programmed to run at the new 4 clocks per cycle if desired.
New hardware features are accessed using special-function registers that do not overlap with standard
80C32 locations. A summary of these SFRs is provided below.
The DS80C320/DS80C323 address memory in an identical fashion to the standard 80C32. Electrical
timing appears different due to the high-speed nature of the product. However, the signals are essentially
the same. Detailed timing diagrams are provided in the Electrical Specifications section.
This data sheet assumes the user is familiar with the basic features of the standard 80C32. In addition to
these standard features, the DS80C320/DS80C323 include many new functions. This data sheet provides
only a summary and overview. Detailed descriptions are available in the High-Speed Microcontroller
User’s Guide.
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Figure 2. Comparative Timing of the DS80C320/DS80C323 and 80C32
DS80C320/DS80C323 TIMING
STANDARD 80C32 TIMING
HIGH-SPEED OPERATION
The DS80C320/DS80C323 are built around a high-speed, 80C32-compatible core. Higher speed comes
not just from increasing the clock frequency but also from a newer, more efficient design.
In this updated core, dummy memory cycles have been eliminated. In a conventional 80C32, machine
cycles are generated by dividing the clock frequency by 12. In the DS80C320/DS80C323, the same
machine cycle is performed in 4 clocks. Thus the fastest instruction, one machine cycle, is executed three
times faster for the same crystal frequency. Note that these are identical instructions. Figure 2 shows a
comparison of the timing differences. The majority of instructions will see the full 3-to-1 speed
improvement. Some instructions will get between 1.5X and 2.4X improvement. Note that all instructions
are faster than the original 80C51. Table 1 shows a summary of the instruction set, including the speed.
The numerical average of all op codes is approximately a 2.5-to-1 speed improvement. Individual
programs are affected differently, depending on the actual instructions used. Speed-sensitive applications
would make the most use of instructions that are three times faster. However, the sheer number of 3-to-1
improved op codes makes dramatic speed improvements likely for any code. The Dual Data Pointer
feature also allows the user to eliminate wasted instructions when moving blocks of memory.
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INSTRUCTION SET SUMMARY
All instructions in the DS80C320/DS80C323 perform the same functions as their 80C32 counterparts.
Their effect on bits, flags, and other status functions is identical. However, the timing of each instruction
is different. This applies both in absolute and relative number of clocks.
For absolute timing of real-time events, the timing of software loops will need to be calculated using the
Table 1. However, counter/timers default to run at the older 12 clocks per increment. Therefore, while
software runs at higher speed, timer-based events need no modification to operate as before. Timers can
be set to run at 4 clocks per increment cycle to take advantage of higher speed operation.
The relative time of two instructions might be different in the new architecture than it was previously. For
example, in the original architecture, the “MOVX A, @DPTR” instruction and the “MOV direct, direct”
instruction used two machine cycles or 24 oscillator cycles. Therefore, they required the same amount of
time. In the DS80C320/DS80C323, the MOVX instruction can be done in two machine cycles or eight
oscillator cycles, but the “MOV direct, direct” uses three machine cycles or 12 oscillator cycles. While
both are faster than their original counterparts, they now have different execution times from each other.
This is because in most cases, the DS80C320/DS80C323 use one cycle for each byte. The user concerned
with precise program timing should examine the timing of each instruction for familiarity with the
changes. Note that a machine cycle now requires just four clocks, and provides one ALE pulse per cycle.
Many instructions require only one cycle, but some require five. In the original architecture, all were one
or two cycles except for MUL and DIV.
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Table 1. Instruction Set Summary
SYMBOL FUNCTION SYMBOL FUNCTION
A Accumulator bit direct bit-address
Rn Register R7 to R0 #data 8-bit constant
direct Internal Register Address #data 16 16-bit constant
addr 16 16-bit destination address
@Ri Internal Register pointed to by R0 or
R1 (except MOVX)
addr 11 11-bit destination address
rel Two’s Complement Offset Byte
INSTRUCTION BYTE
OSCILLATOR
CYCLES INSTRUCTION BYTE
OSCILLATOR
CYCLES
ARITHMATIC INSTRUCTIONS
ADD A, Rn 1 4 INC A 1 4
ADD A, direct 2 8 INC Rn 1 4
ADD A, @Ri 1 4 INC direct 2 8
ADD A, #data 2 8 INC @Ri 1 4
ADDC A, Rn 1 4 INC DPTR 1 12
ADDC A, direct 2 8 DEC A 1 4
ADDC A, @Ri 1 4 DEC Rn 1 4
ADDC A, #data 2 8 DEC direct 2 8
SUBB A, Rn 1 4 DEC @Ri 1 4
SUBB A, direct 2 8 MUL AB 1 20
SUBB A, @Ri 1 4 DIV AB 1 20
SUBB A, #data 2 8 DA A 1 4
LOGICAL INSTRUCTIONS
ANL A, Rn 1 4 XRL A, Rn 1 4
ANL A, direct 2 8 XRL A, direct 2 8
ANL A, @Ri 1 4 XRL A, @Ri 1 4
ANL A, #data 2 8 XRL A, #data 2 8
ANL direct, A 2 8 XRL direct, A 2 8
ANL direct, #data 3 12 XRL direct, #data 3 12
ORL A, Rn 1 4 CLR A 1 4
ORL A, direct 2 8 CPL A 1 4
ORL A, @Ri 1 4 RL A 1 4
ORL A, #data 2 8 RLC A 1 4
ORL direct, A 2 8 RR A 1 4
ORL direct, #data 3 12 RRC A 1 4
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Table 1. Instruction Set Summary (continued)
INSTRUCTION BYTE
OSCILLATOR
CYCLES INSTRUCTION BYTE
OSCILLATOR
CYCLES
DATA TRANSFER INSTRUCTIONS
MOV A, Rn 1 4 MOVC A,
@A+DPTR 1 12
MOV A, direct 2 8 MOVC A, @A+PC 1 12
MOV A, @Ri 1 4 MOVX A, @Ri 1 8–36*
MOV A, #data 2 8 MOVX A, @DPTR 1 8–36*
MOV Rn, A 1 4 MOVX @Ri, A 1 8–36*
MOV Rn, direct 2 8 MOVX @DPTR, A 1 8–36*
MOV Rn, #data 2 8 PUSH direct 2 8
MOV direct, A 2 8 POP direct 2 8
MOV direct, Rn 2 8 XCH A, Rn 1 4
MOV direct1, direct2 3 12 XCH A, direct 2 8
MOV direct, @Ri 2 8 XCH A, @Ri 1 4
MOV direct, #data 3 12 XCHD A, @Ri 1 4
MOV @Ri, A 1 4
MOV @Ri, direct 2 8
MOV @Ri, #data 2 8
MOV DPTR, #data 16 3 12
BIT MANIPULATION INSTRUCTIONS
CLR C 1 4 ANL C, bit 2 8
CLR bit 2 8 ANL C, bit 2 8
SETB C 1 4 ORL C, bit 2 8
SETB bit 2 8 ORL C, bit 2 8
CPL C 1 4 MOV C, bit 2 8
CPL bit 2 8 MOV bit, C 2 8
PROGRAM BRANCHING INSTRUCTIONS
ACALL addr 11 2 12 CJNE A, direct, rel 3 16
LCALL addr 16 3 16 CJNE A, #data, rel 3 16
RET 1 16 CJNE Rn, #data, rel 3 16
RETI 1 16 CJNE Ri, #data, rel 3 16
AJMP addr 11 2 12 NOP 1 4
LJMP addr 16 3 16 JC rel 2 12
SJMP rel 2 12 JNC rel 2 12
JMP @A+DPTR 1 12 JB bit, rel 3 16
JZ rel 2 12 JNB bit, rel 3 16
JNZ rel 2 12 JBC bit, rel 3 16
DJNZ Rn, rel 2 12
DJNZ direct, rel 3 16
*User selectable.
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Table 1 shows the speed for each class of instruction. Note that many of the instructions have multiple op
codes. There are 255 op codes for 111 instructions. Of the 255 op codes, 159 are three times faster than
the original 80C32. While a system that emphasizes those instructions will see the most improvement, the
large total number that receive a 3 to 1 improvement assure a dramatic speed increase for any system. The
speed improvement summary is provided below.
SPEED ADVANTAGE SUMMARY
#OP CODES SPEED
IMPROVEMENT
159 3.0 x
51 1.5 x
43 2.0 x
2 2.4 x
255 Average: 2.5
MEMORY ACCESS
The DS80C320/DS80C323 do not contain on-chip ROM and 256 bytes of scratchpad RAM. Off-chip
memory is accessed using the multiplexed address/data bus on P0 and the MSB address on P2. Figure 3
shows a typical memory connection. Timing diagrams are provided in the Electrical Specifications
section. Program memory (ROM) is accessed at a fixed rate determined by the crystal frequency and the
actual instructions. As previously mentioned, an instruction cycle requires 4 clocks. Data memory (RAM)
is accessed according to a variable-speed MOVX instruction as described below.
Figure 3. Typical Memory Connection
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STRETCH MEMORY CYCLE
The DS80C320/DS80C323 allow the application software to adjust the speed of data memory access. The
microcontroller is capable of performing the MOVX in as little as two instruction cycles. However, this
value can be stretched as needed so that both fast memory and slow memory or peripherals can be
accessed with no glue logic. Even in high-speed systems, it may not be necessary or desirable to perform
data memory access at full speed. In addition, there are a variety of memory-mapped peripherals such as
LCD displays or UARTs that are not fast.
The Stretch MOVX is controlled by the Clock Control Register at SFR location 8Eh as described below.
This allows the user to select a stretch value between 0 and 7. A Stretch of 0 will result in a two-machine
cycle MOVX. A Stretch of 7 will result in a MOVX of nine machine cycles. Software can dynamically
change this value depending on the particular memory or peripheral.
On reset, the Stretch value will default to 1, resulting in a three-cycle MOVX. Therefore, RAM access
will not be performed at full speed. This is a convenience to existing designs that may not have fast RAM
in place. When maximum speed is desired, the software should select a Stretch value of 0. When using
very slow RAM or peripherals, a larger stretch value can be selected. Note that this affects data memory
only and the only way to slow program memory (ROM) access is to use a slower crystal.
Using a Stretch value between 1 and 7 causes the microcontroller to stretch the read/write strobe and all
related timing. This results in a wider read/write strobe allowing more time for memory/peripherals to
respond. The timing of the variable speed MOVX is shown in the Electrical Specifications section. Note
that full speed access is not the reset default case. Table 2 shows the resulting strobe widths for each
Stretch value. The memory stretch is implemented using the Clock Control special-function register at
SFR location 8Eh. The stretch value is selected using bits CKCON.2–0. In the table, these bits are
referred to as M2 through M0. The first stretch (default) allows the use of common 120ns or 150ns RAMs
without dramatically lengthening the memory access.
Table 2. Data Memory Cycle Stretch Values
CKCON.2–0
MD2 MD1 MD0
MEMORY
CYCLES
RD or WR STROBE
WIDTH IN CLOCKS
STROBE WIDTH
TIME AT 25MHz
(ns)
0 0 0 2 2 80
0 0 1 3 (default) 4 160
0 1 0 4 8 320
0 1 1 5 12 480
1 0 0 6 16 640
1 0 1 7 20 800
1 1 0 8 24 960
1 1 1 9 28 1120
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DUAL DATA POINTER
Data memory block moves can be accelerated using the Dual Data Pointer (DPTR). The standard 8032
DPTR is a 16-bit value that is used to address off-chip data RAM or peripherals. In the
DS80C320/DS80C323, the standard 16-bit data pointer is called DPTR0 and is located at SFR addresses
82h and 83h. These are the standard locations. The new DPTR is located at SFR 84h and 85h and is
called DPTR1. The DPTR Select bit (DPS) chooses the active pointer and is located at the LSB of the
SFR location 86h. No other bits in register 86h have any effect and are set to 0. The user switches
between data pointers by toggling the LSB of register 86h. The increment (INC) instruction is the fastest
way to accomplish this. All DPTR-related instructions use the currently selected DPTR for any activity.
Therefore only one instruction is required to switch from a source to a destination address. Using the
Dual-Data Pointer saves code from needing to save source and destination addresses when doing a block
move. Once loaded, the software simply switches between DPTR and 1. The relevant register locations
are as follows.
DPL 82h Low byte original DPTR
DPH 83h High byte original DPTR
DPL1 84h Low byte new DPTR
DPH1 85h High byte new DPTR
DPS 86h DPTR Select (LSB)
Sample code listed below illustrates the saving from using the dual DPTR. The example program was
original code written for an 8051 and requires a total of 1869 DS80C320/DS80C323 machine cycles. This
takes 299ms to execute at 25MHz. The new code using the Dual DPTR requires only 1097 machine
cycles taking 175.5ms. The Dual DPTR saves 772 machine cycles or 123.5ms for a 64-byte block move.
Since each pass through the loop saves 12 machine cycles when compared to the single DPTR approach,
larger blocks gain more efficiency using this feature.
64-Byte Block Move without Dual Data Pointer
; SH and SL are high and low byte source address.
; DH and DL are high and low byte of destination address. # CYCLES
MOV R5, #64d ; NUMBER OF BYTES TO MOVE 2
MOV DPTR, #SHSL ; LOAD SOURCE ADDRESS 3
MOV R1, #SL ; SAVE LOW BYTE OF SOURCE 2
MOV R2, #SH ; SAVE HIGH BYTE OF SOURCE 2
MOV R3, #DL ; SAVE LOW BYTE OF DESTINATION 2
MOV R4, #DH ; SAVE HIGH BYTE OF DESTINATION 2
MOVE:
; THIS LOOP IS PERFORMED THE NUMBER OF TIMES LOADED INTO R5, IN THIS EXAMPLE 64
MOVX A, @DPTR ; READ SOURCE DATA BYTE 2
MOV R1, DPL ; SAVE NEW SOURCE POINTER 2
MOV R2, DPH ; 2
MOV DPL, R3 ; LOAD NEW DESTINATION 2
MOV DPH, R4 ; 2
MOVX @DPTR, A ; WRITE DATA TO DESTINATION 2
INC DPTR ; NEXT DESTINATION ADDRESS 3
MOV R3, DPL ; SAVE NEW DESTINATION POINTER 2
MOV R4, DPH ; 2
MOV DPL, R1 ; GET NEW SOURCE POINTER 2
MOV DPH, R2 ; 2
INC DPTR ; NEXT SOURCE ADDRESS 3
DJNZ R5, MOVE ; FINISHED WITH TABLE? 3
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64-Byte Block Move with Dual Data Pointer
; SH and SL are high and low byte source address.
; DH and DL are high and low byte of destination address.
; DPS is the data pointer select. Reset condition is DPS=0, DPTR0 is selected.
# CYCLES
EQU DPS, #86h ; TELL ASSEMBLER ABOUT DPS
MOV R5, #64 ; NUMBER OF BYTES TO MOVE 2
MOV DPTR, #DHDL ; LOAD DESTINATION ADDRESS 3
INC DPS ; CHANGE ACTIVE DPTR 2
MOV DPTR, #SHSL ; LOAD SOURCE ADDRESS 2
MOVE:
; THIS LOOP IS PERFORMED THE NUMBER OF TIMES LOADED INTO R5, IN THIS EXAMPLE 64
MOVX A, @DPTR ; READ SOURCE DATA BYTE 2
INC DPS ; CHANGE DPTR TO DESTINATION 2
MOVX @DPTR, A ; WRITE DATA TO DESTINATION 2
INC DPTR ; NEXT DESTINATION ADDRESS 3
INC DPS ; CHANGE DATA POINTER TO SOURCE 2
INC DPTR ; NEXT SOURCE ADDRESS 3
DJNZ R5, MOVE ; FINISHED WITH TABLE? 3
PERIPHERAL OVERVIEW
Peripherals in the DS80C320/DS80C323 are accessed using the SFRs. The devices provide several of the
most commonly needed peripheral functions in microcomputer-based systems. These functions are new
to the 80C32 family and include a second serial port, power-fail reset, power-fail interrupt, and a
programmable watchdog timer. These are briefly described in the following paragraphs. More details are
available in the High-Speed Microcontroller User’s Guide.
SERIAL PORTS
The DS80C320/DS80C323 provide a serial port (UART) that is identical to the 80C32. Many
applications require serial communication with multiple devices. Therefore, a second hardware serial port
is provided that is a full duplicate of the standard one. It optionally uses pins P1.2 (RXD1) and P1.3
(TXD1). This port has duplicate control functions included in new SFR locations. The second serial port
operates in a comparable manner with the first. Both can operate simultaneously but can be at different
baud rates.
The second serial port has similar control registers (SCON1 at C0h, SBUF1 at C1h) to the original. One
difference is that for timer-based baud rates, the original serial port can use Timer 1 or Timer 2 to
generate baud rates. This is selected via SFR bits. The new serial port can only use Timer 1.
TIMER-RATE CONTROL
One important difference exists between the DS80C320/DS80C323 and 80C32 regarding timers. The
original 80C32 used a 12 clock-per-cycle scheme for timers and consequently for some serial baud rates
(depending on the mode). The DS80C320/DS80C323 architecture normally runs using 4 clocks per cycle.
However, in the area of timers, it will default to a 12 clock-per-cycle scheme on a reset. This allows
existing code with real-time dependencies such as baud rates to operate properly. If an application needs
higher speed timers or serial baud rates, the timers can be set to run at the 4-clock rate.
The Clock Control register (CKCON - 8Eh) determines these timer speeds. When the relevant CKCON
bit is a logic 1, the device uses 4 clocks per cycle to generate timer speeds. When the control bit is set to a
0, the device uses 12 clocks for timer speeds. The reset condition is a 0. CKCON.5 selects the speed of
Timer 2. CKCON.4 selects Timer 1 and CKCON.3 selects Timer 0. Note that unless a user desires very
fast timing, it is unnecessary to alter these bits. Note that the timer controls are independent.
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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POWER-FAIL RESET
The DS80C320/DS80C323 incorporate a precision bandgap voltage reference to determine when VCC is
out of tolerance. While powering up, internal circuits will hold the device in a reset state until VCC rises
above the VRST reset threshold. Once VCC is above this level, the oscillator will begin running. An internal
reset circuit will then count 65,536 clocks to allow time for power and the oscillator to stabilize. The
microcontroller will then exit the reset condition. No external components are needed to generate a power
on reset. During power-down or during a severe power glitch, as VCC falls below VRST, the
microcontroller will also generate its own reset. It will hold the reset condition as long as power remains
below the threshold. This reset will occur automatically, needing no action from the user or from the
software. See the Electrical Specifications section for the exact value of VRST.
POWER-FAIL INTERRUPT
The same reference that generates a precision reset threshold can also generate an optional early warning
Power-fail Interrupt (PFI). When enabled by the application software, this interrupt always has the
highest priority. On detecting that the VCC has dropped below VPFW and that the PFI is enabled, the
processor will vector to ROM address 0033h. The PFI enable is located in the Watchdog Control SFR
(WDCON to D8h). Setting WDCON.5 to logic 1 will enable the PFI. The application software can also
read a flag at WDCON.4. This bit is set when a PFI condition has occurred. The flag is independent of the
interrupt enable and software must manually clear it.
WATCHDOG TIMER
For applications that cannot afford to run out of control, the DS80C320/DS80C323 incorporate a
programmable watchdog timer circuit. The watchdog timer circuit resets the microcontroller if software
fails to reset the watchdog before the selected time interval has elapsed. The user selects one of four
timeout values. After enabling the watchdog, software must reset the timer prior to expiration of the
interval, or the CPU will be reset. Both the Watchdog Enable and the Watchdog Reset bits are protected
by a “Timed Access” circuit. This prevents accidentally clearing the watchdog. Timeout values are
precise since they are related to the crystal frequency as shown in Table 3. For reference, the time periods
at 25MHz are also shown.
The watchdog timer also provides a useful option for systems that may not require a reset. If enabled,
then 512 clocks before giving a reset, the watchdog will give an interrupt. The interrupt can also serve as
a convenient time-base generator, or be used to wake-up the processor from Idle mode. The watchdog
function is controlled in the Clock Control (CKCON to 8Eh), Watchdog Control (WDCON to D8h), and
Extended Interrupt Enable (EIE to E8h) SFRs. CKCON.7 and CKCON.6 are called WD1 and WD0,
respectively, and are used to select the watchdog timeout period as shown in Table 3.
Table 3. Watchdog Timeout Values
WD1 WD0 INTERRUPT
TIMEOUT
TIME (at
25MHz)
RESET
TIMEOUT
TIME
(at 25MHz)
0 0 217 clocks 5.243ms 217 + 512 clocks 5.263ms j
0 1 220 clocks 41.94ms 220 + 512 clocks 41.96ms
1 0 223 clocks 335.54ms 223 + 512 clocks 335.56ms
1 1 226 clocks 2684.35ms 226 + 512 clocks 2684.38ms
As Table 3 shows, the watchdog timer uses the crystal frequency as a time base. A user selects one of
four counter values to determine the timeout. These clock counter lengths are 217 = 131,072 clocks;
220 = 1,048,576; 223 = 8,388,608 clocks; or 226 = 67,108,864 clocks. The times shown in Table 4 are with
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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a 25MHz crystal frequency. Note that once the counter chain has reached a conclusion, the optional
interrupt is generated. Regardless of whether the user enables this interrupt, there are then 512 clocks left
until a reset occurs. There are 5 control bits in special function registers that affect the Watchdog Timer
and two status flags that report to the user. The Reset Watchdog Timer bit (WDCON.0) should be
asserted prior to modifying the Watchdog Timer Mode Select bits (WD1, WD0) to avoid corruption of
the watchdog count.
WDIF (WDCON.3) is the interrupt flag that is set when there are 512 clocks remaining until a reset
occurs. WTRF (WDCON.2) is the flag that is set when a Watchdog reset has occurred. This allows the
application software to determine the source of a reset.
Setting the EWT (WDCON.1) bit enables the Watchdog Timer. The bit is protected by timed access.
Setting the RWT (WDCON.0) bit restarts the Watchdog Timer for another full interval. Application
software must set this bit prior to the timeout. As mentioned previously, WD1 and 0 (CKCON .7 and 6)
select the timeout. Finally, the Watchdog Interrupt is enabled using EWDI (EIE.4).
INTERRUPTS
The DS80C320/DS80C323 provide 13 sources of interrupt with three priority levels. The Power-fail
Interrupt (PFI), if enabled, always has the highest priority. There are two remaining user-selectable
priorities: high and low. If two interrupts that have the same priority occur simultaneously, the natural
precedence given in Table 4 determines which is acted upon. Except for the PFI, all interrupts that are
new to the 8051 family have a lower natural priority than the originals.
Table 4. Interrupt Priority
NAME FUNCTION VECTOR
NATURAL
PRIORITY OLD/NEW
PFI Power-Fail Interrupt 33h j 1 New
INT0 External Interrupt 0 03h 2 Old
TF0 Timer 0 0Bh 3 Old
INT1 External Interrupt 1 13h 4 Old
TF1 Timer 1 1Bh 5 Old
SCON0 TI0 or RI0 from Serial Port 0 23h 6 Old
TF2 Timer 2 2Bh 7 Old
SCON1 TI1 or RI1 from Serial Port 1 3Bh 8 New
INT2 External Interrupt 2 43h 9 New
INT3 External Interrupt 3 4Bh 10 New
INT4 External Interrupt 4 53h 11 New
INT5 External Interrupt 5 5Bh 12 New
WDTI Watchdog Timeout Interrupt 63h 13 New
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POWER MANAGEMENT
The DS80C320/DS80C323 provide the standard Idle and power-down (Stop) modes that are available on
the standard 80C32. However, the device has enhancements that make these modes more useful, and
allow more power saving.
The Idle mode is invoked by setting the LSB of the Power Control register (PCON to 87h). Idle will leave
internal clocks, serial port and timer running. No memory access will be performed so power is
dramatically reduced. Since clocks are running, the Idle power consumption is related to crystal
frequency. It should be approximately one-half the operational power. The CPU can exit the Idle state
with any interrupt or a reset.
The power-down or Stop mode is invoked by setting the PCON.1 bit. Stop mode is a lower power state
than Idle since it turns off all internal clocking. The ICC of a standard Stop mode is approximately 1 µA
but is specified in the Electrical Specifications section. The CPU will exit Stop mode from an external
interrupt or a reset condition.
Note that internally generated interrupts (timer, serial port, watchdog) are not useful in Idle or Stop since
they require clocking activity.
IDLE MODE ENHANCEMENTS
A simple enhancement to Idle mode makes it substantially more useful. The innovation involves not the
Idle mode itself, but the watchdog timer. As mentioned above, the Watchdog Timer provides an optional
interrupt capability. This interrupt can provide a periodic interval timer to bring the
DS80C320/DS80C323 out of Idle mode. This can be useful even if the Watchdog is not normally used.
By enabling the Watchdog Timer and its interrupt prior to invoking Idle, a user can periodically come out
of Idle perform an operation, then return to Idle until the next operation. This will lower the overall power
consumption. When using the Watchdog Interrupt to cancel the Idle state, make sure to restart the
Watchdog Timer or it will cause a reset.
STOP MODE ENHANCEMENTS
The DS80C320/DS80C323 provide two enhancements to the Stop mode. As documented above, the
device provides a bandgap reference to determine Power-fail Interrupt and Reset thresholds. The default
state is that the bandgap reference is off when Stop mode is invoked. This allows the extremely low
power state mentioned above. A user can optionally choose to have the bandgap enabled during Stop
mode. This means that PFI and power-fail reset will be activated and are valid means for leaving Stop
mode.
In Stop mode with the bandgap on, ICC will be approximately 50mA compared with 1mA with the bandgap
off. If a user does not require a Power-fail Reset or Interrupt while in Stop mode, the bandgap can remain
turned off. Note that only the most power sensitive applications should turn off the bandgap, as this
results in an uncontrolled power-down condition.
The control of the bandgap reference is located in the Extended Interrupt Flag register (EXIF to 91h).
Setting BGS (EXIF.0) to a 1 will leave the bandgap reference enabled during Stop mode. The default or
reset condition is with the bit at a logic 0. This results in the bandgap being turned off during Stop mode.
Note that this bit has no control of the reference during full power or Idle modes. Be aware that the
DS80C320 and DS80C323 require that the reset watchdog timer bit (RWT;WDCON.0) be set
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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immediately preceding the setting of the Stop bit to guarantee a correct power-on delay when exiting Stop
mode.
The second feature allows an additional power saving option. This is the ability to start instantly when
exiting Stop mode. It is accomplished using an internal ring oscillator that can be used when exiting Stop
mode in response to an interrupt. The benefit of the ring oscillator is as follows.
Using Stop mode turns off the crystal oscillator and all internal clocks to save power. This requires that
the oscillator be restarted when exiting Stop mode. Actual start-up time is crystal dependent, but is
normally at least 4ms. A common recommendation is 10ms. In an application that will wakeup, perform a
short operation, then return to sleep, the crystal startup can be longer than the real transaction. However,
the ring oscillator will start instantly. The user can perform a simple operation and return to sleep before
the crystal has even stabilized. If the ring is used to start and the processor remains running, hardware will
automatically switch to the crystal once a power-on reset interval (65,536 clocks) has expired. This value
is used to guarantee stability even though power is not being cycled.
If the user returns to Stop mode prior to switching of crystal, then all clocks will be turned off again. The
ring oscillator runs at approximately 3MHz (1.5MHz at 3V) but will not be a precision value. No real-
time precision operations (including serial communication) should be conducted during this ring period.
Figure 4 shows how the operation would compare when using the ring, and when starting up normally.
The default state is to come out of Stop mode without using the ring oscillator.
This function is controlled using the RGSL - Ring Select bit at EXIF.1 (EXIF to 91h). When EXIF.1 is
set, the ring oscillator will be used to come out of Stop mode quickly. As mentioned above, the processor
will automatically switch from the ring (if enabled) to the crystal after a delay of 65,536 crystal clocks.
For a 3.57MHz crystal, this is approximately 18ms. The processor sets a flag called RGMD - Ring Mode
to tell software that the ring is being used. This bit at EXIF.2 will be logic 1 when the ring is in use. No
serial communication or precision timing should be attempted while this bit is set, since the operating
frequency is not precise.
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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Figure 4. Ring Oscillator Startup
TIMED ACCESS PROTECTION
Selected SFR bits are critical to operation, making it desirable to protect against an accidental write
operation. The Timed Access procedure prevents an errant CPU from accidentally altering a bit that
would cause difficulty. The Timed Access procedure requires that the write of a protected bit be preceded
by the following instructions:
MOV 0C7h, #0AAh
MOV 0C7h, #55h
By writing an AAh followed by a 55h to the Timed Access register (location C7h), the hardware opens a
three-cycle window that allows software to modify one of the protected bits. If the instruction that seeks
to modify the protected bit is not immediately proceeded by these instructions, the write will not take
effect. The protected bits are:
EXIF.0 BGS Bandgap Select
WDCON.6 POR Power-on Reset flag
WDCON.1 EWT Enable Watchdog
WDCON.0 RWT Reset Watchdog
WDCON.3 WDIF Watchdog Interrupt Flag
DIAGRAM ASSUMES THAT THE OPERATION FOLLOWING STOP REQUIRES LESS THAN 18ms COMPLETE.
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SPECIAL-FUNCTION REGISTERS
Most special features of the DS80C320/DS80C323 or 80C32 are controlled by bits in the SFRs, allowing
the devices to add many features but use the same instruction set. When writing software to use a new
feature, the SFR must be defined to an assembler or compiler using an equate statement. This is the only
change needed to access the new function. The DS80C320/DS80C323 duplicate the SFRs that are
contained in the standard 80C32. Table 5 shows the register addresses and bit locations. Many are
standard 80C32 registers. The High-Speed Microcontroller User’s Guide describes all SFRs.
Table 5. Special-Function Register Locations
REGISTER BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 ADDRESS
SP 81h
DPL 82h
DPH 83h
DPL1 84h
DPH1 85h
DPS 0 0 0 0 0 0 0 SEL
86h
PCON SMOD_0
SMOD0 — — GF1 GF0 STOP IDLE 87h
TCON TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 88h
TMOD GATE
C/ T M1 M0 GATE
C/ T M1 M0 89h
TL0 8Ah
TL1 8Bh
TH0 8Ch
TH1 8Dh
CKCON WD1 WD0 T2M T1M T0M MD2 MD1 MD0 8Eh
P1 P1.7 P1.6 P1.5 P1.4 P1.3 P1.2 P1.1 P1.0 90h
EXIF IE5 IE4 IE3 IE2 — RGMD RGSL BGS
91h
SCON0 SM0/FE_0 SM1_0 SM2_0 REN_0 TB8_0 RB8_0 TI_0 RI_0 98h
SBUF0 99h
P2 P2.0 P2.6 P2.5 P2.4 P2.3 P2.2 P2.1 P2.0 A0h
IE EA ES1 ET2 ES0 ET1 EX1 ET0 EX0 A8h
SADDR0 A9h
SADDR1 AAh
P3 P3.7 P3.6 P3.5 P3.4 P3.3 P3.2 P3.1 P3.0 B0h
IP — PS1 PT2 PS0 PT1 PX1 PT0 PX0 B8h
SADEN0 B9h
SADEN1 BAh
SCON1 SM0/FE_0 SM1_0 SM2_0 REN_0 TB8_0 RB8_0 TI_0 RI_0 C0h
SBUF1 C1h
STATUS PIP HIP LIP 1 1 1 1 1 C5h
TA C7h
T2CON TF2 EXF2 RCLK TCLK EXEN2 TR2
C/ T2 CP/ RL2 C8h
T2MOD — — — — — — T2OE DCEN C9h
RCAP2L CAh
RCAP2H CBh
TL2 CCh
TH2 CDh
PSW CY AC F0 RS1 RS0 OV FL P D0h
WDCON SMOD_1 POR EPFI PFI WDIF WTRF EWT RWT D8h
ACC E0h
EIE — — — EWDI EX5 EX4 EX3 EX2 E8h
B F0h
EIP — — — PWDI PX5 PX4 PX3 PX2 F8h
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ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Pin Relative to Ground…………………………………………-0.3V to (VCC + 0.5V)
Voltage Range on VCC Relative to Ground……………………………………………………..-0.3V to +6.0V
Operating Temperature Range………………………………………………………………….-40°C to +85°C
Storage Temperature Range…………………………………………………………………..-55°C to +125°C
Soldering Temperature…………………………………………….See IPC/JEDEC J-STD-020 Specification
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the
operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of
time may affect reliability.
DC ELECTRICAL CHARACTERISTICS—DS80C320
(VCC = 4.5V to 5.5V, TA = -40°C to +85°C.)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Operating Supply Voltage VCC 4.5 5.0 5.5 V 1
Power-Fail Warning Voltage VPFW 4.25 4.38 4.55 V 1
Minimum Operating Voltage VRST 4.0 4.1 4.25 V 1, 12
Supply Current Active Mode at 25MHz ICC 30 45 mA 2
Supply Current Idle Mode at 25MHz IIDLE 15 25 mA 3
Supply Current Active Mode at 33MHz ICC 35 mA 2
Supply Current Idle Mode at 33MHz IIDLE 20 mA 3
Supply Current Stop Mode,
Bandgap Reference Disabled ISTOP 0.01 1 µA 4
Supply Current Stop Mode,
Bandgap Reference Enabled ISPBG 50 80 µA 4, 10
Input Low Level VIL -0.3 +0.8 V 1
Input High Level (Except XTAL1 and RST) VIH1 2.0 VCC + 0.3 V 1
Input High Level XTAL1 and RST VIH2 3.5 VCC + 0.3 V 1
Output-Low Voltage Ports 1, 3
at IOL = 1.6mA VOL1 0.45 V 1
Output-Low Voltage Ports 0, 2, ALE, PSEN
at IOL = 3.2mA VOL2 0.45 V 1, 5
Output-High Voltage Ports 1, 3, ALE, PSEN
at IOH = -50µA VOH1 2.4 V 1, 6
Output High Voltage Ports 1, 3
at IOH = -1.5mA VOH2 2.4 V 1, 7
Output-High Voltage Ports 0, 2, ALE, PSEN
at IOH = -8mA VOH3 2.4 V 1, 5
Input Low Current Ports 1, 3 at 0.45V IIL -55 µA 11
Transition Current from 1 to 0
Ports 1, 3 at 2V ITL -650 µA 8
Input Leakage Port 0, Bus Mode IL -300 +300 µA 9
RST Pulldown Resistance RRST 50 170
kW
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NOTES FOR DS80C320 DC ELECTRICAL CHARACTERISTICS
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40°C
are guaranteed by design and are not production tested.
1. All voltages are referenced to ground.
2. Active current is measured with a 25MHz clock source driving XTAL1, VCC = RST = 5.5V, all other pins
disconnected.
3. Idle mode current is measured with a 25MHz clock source driving XTAL1, VCC = 5.5V, RST at ground, all
other pins disconnected.
4. Stop mode current measured with XTAL1 and RST grounded, VCC = 5.5V, all other pins disconnected.
5. When addressing external memory. This specification only applies to the first clock cycle following transition.
6. RST = VCC. This condition mimics operation of pins in I/O mode.
7. During a 0-to-1 transition, a one-shot drives the ports hard for two clock cycles. This measurement reflects port
in transition mode.
8. Ports 1 and 3 source transition current when being pulled down externally. It reaches its maximum at
approximately 2V.
9. 0.45<VIN<VCC. Not a high-impedance input. This port is a weak address holding latch because Port 0 is
dedicated as an address bus on the DS80C320. Peak current occurs near the input transition point of the latch,
approximately 2V.
10. Over the industrial temperature range, this specification has a maximum value of 200mA.
11. This is the current required from an external circuit to hold a logic low level on an I/O pin while the
corresponding port latch bit is set to 1. This is only the current required to hold the low level; transitions from 1
to 0 on an I/O pin will also have to overcome the transition current.
12. Device operating range is 4.5V to 5.5V; however, device is tested to 4.0V to ensure proper operation at
minimum VRST.
TYPICAL ICC vs. FREQUENCY
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AC CHARACTERISTICS—DS80C320
33MHz VARIABLE CLOCK
PARAMETER SYMBOL
MIN MAX MIN MAX
UNITS
External
Oscillator 0 33 0 33
Oscillator
Frequency External
Crystal
1/tCLCL
1 33 1 33
MHz
ALE Pulse Width tLHLL 34 1.5tCLCL-11 ns
Port 0 Address Valid to
ALE Low tAVLL 4 0.5tCLCL-11 ns
Address Hold After
ALE Low tLLAX1 2 (Note 5) 0.25tCLCL-5 (Note 5) ns
Address Hold After
ALE Low for MOVX WR tLLAX2 6 0.5tCLCL-9 ns
ALE Low to Valid
Instruction In tLLIV 49 2.5tCLCL-27 ns
ALE Low to PSEN Low tLLPL 0.5 0.25tCLCL-7 ns
PSEN Pulse Width tPLPH 61 2.25tCLCL-7 ns
PSEN Low to Valid
Instruction In tPLIV 48 2.25tCLCL-21 ns
Input Instruction Hold
After PSEN tPXIX 0 0 ns
Input Instruction Float
After PSEN tPXIZ 25 tCLCL-5 ns
Port 0 Address to Valid
Instruction In tAVIV1 64 3tCLCL-27 ns
Port 2 Address to Valid
Instruction In tAVIV2 73 3.5tCLCL-33 ns
PSEN Low to Address Float tPLAZ (Note 5) (Note 5) ns
NOTES FOR DS80C320 AC ELECTRICAL CHARACTERISTICS
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40°C
are guaranteed by design and are not production tested. AC electrical characteristics assume 50% duty cycle for the oscillator,
oscillator frequency > 16MHz, and are not 100% tested, but are guaranteed by design.
1. All signals rated over operating temperature at 33MHz.
2. All signals characterized with load capacitance of 80pF except Port 0, ALE, PSEN , RD and WR at 100pF.
Note that loading should be approximately equal for valid timing.
3. Interfacing to memory devices with float times (turn off times) over 30ns may cause contention. This will not
damage the parts but will cause an increase in operating current.
4. Specifications assume a 50% duty cycle for the oscillator. Port 2 timing will change with the duty cycle
variations.
5. Address is held in a weak latch until over driven by external memory.
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MOVX CHARACTERISTICS—DS80C320
VARIABLE CLOCK
PARAMETER SYMBOL
MIN MAX
UNITS STRETCH
2tCLCL-11 tMCS=0
RD Pulse Width tRLRH tMCS-11
ns tMCS>0
2tCLCL-11 tMCS=0
WR Pulse Width tWLWH tMCS-11
ns tMCS>0
2tCLCL-25 tMCS=0
RD Low to Valid Data In tRLDV t
MCS-25 ns tMCS>0
Data Hold After Read tRHDX 0 ns
t
CLCL-5 tMCS=0
Data Float After Read tRHDZ 2tCLCL-5 ns tMCS>0
2.5tCLCL-27 tMCS=0
ALE Low to Valid Data In tLLDV 1.5tCLCL-28+tMCS ns tMCS>0
3tCLCL-27 tMCS=0 Port 0 Address to Valid Data
In tAVDV1 2tCLCL-31+tMCS ns tMCS>0
3.5tCLCL-32 tMCS=0
Port 2 Address to Valid Data
In tAVDV2 2.5tCLCL-34+tMCS ns tMCS>0
0.5tCLCL-8 0.5tCLCL+6 tMCS=0
ALE Low to RD or WR Low tLLWL 1.5tCLCL-7 1.5tCLCL+8 ns tMCS>0
tCLCL-11 tMCS=0
Port 0 Address Valid to RD or
WR Low tAVWL1 2tCLCL-10
ns tMCS>0
1.5tCLCL-9 tMCS=0
Port 2 Address Valid to RD or
WR Low tAVWL2 2.5tCLCL-13 ns tMCS>0
-9 tMCS=0
Data Valid to WR Transition tQVWX tCLCL-10
ns tMCS>0
tCLCL-12 tMCS=0
Data Hold After Write tWHQX 2tCLCL-7
ns tMCS>0
RD Low to Address Float tRLAZ (Note 5) ns
0 10 tMCS=0
RD or WR High to ALE
High tWHLH tCLCL-5 tCLCL+11 ns tMCS>0
Note: tMCS is a time period related to the Stretch memory cycle selection. The following table shows the value of
tMCS for each Stretch selection.
M2 M1 M0 MOVX CYCLES tMCS
0 0 0 2 machine cycles 0
0 0 1 3 machine cycles (default) 4 tCLCL
0 1 0 4 machine cycles 8 tCLCL
0 1 1 5 machine cycles 12 tCLCL
1 0 0 6 machine cycles 16 tCLCL
1 0 1 7 machine cycles 20 tCLCL
1 1 0 8 machine cycles 24 tCLCL
1 1 1 9 machine cycles 28 tCLCL
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DC ELECTRICAL CHARACTERISTICS—DS80C323
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Operating Supply Voltage VCC 2.7 3.0 5.5 V 1
Power-Fail Warning Voltage VPFW 2.6 2.7 2.8 V 1
Minimum Operating Voltage VRST 2.5 2.6 2.7 V 1, 12
Supply Current Active Mode at 18MHz ICC 10 mA 2
Supply Current Idle Mode at 18MHz IIDLE 6 mA 3
Supply Current Stop Mode,
Bandgap Reference Disabled ISTOP 0.1 µA 2
Supply Current Stop Mode,
Bandgap Reference Enabled ISPBG 40 µA 4, 10
Input Low Level VIL -0.3 +0.2 x VCC V 1
Input High Level
(Except XTAL1 and RST) VIH1 0.7 x VCC V
CC+0.3 V 1
Input High Level XTAL1 and RST VIH2 0.7 x VCC
+0.25V V
CC+0.3 V 1
Output Low Voltage Ports 1, 3
at IOL = 1.6mA VOL1 0.4 V 1
Output Low Voltage Ports 0, 2,
PSEN /ALE at IOL = 3.2mA VOL2 0.4 V 1, 5
Output High Voltage Ports 1, 3,
PSEN /ALE at IOH = -15µA VOH1 VDD
-0.4V V 1, 6
Output High Voltage Ports 1, 3
at IOH = -1.5mA VOH2 VDD
-0.4V V 1, 7
Output High Voltage Ports 0, 2,
PSEN /ALE at IOH = -2mA VOH3 VDD
-0.4V V 1, 5
Input Low Current Ports 1, 3 at 0.45V IIL -30 µA 11
Transition Current from 1 ³ 0,
Ports 1, 3 at 2V ITL -400 µA 8
Input Leakage Port 0, Bus Mode IL -300 +300 µA 9
RST Pulldown Resistance RRST 50 170
kW
NOTES FOR DS80C323 DC ELECTRICAL CHARACTERISTICS
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40°C
are guaranteed by design and are not production tested. Device operating range is 2.7V to 5.5V. DC electrical specifications are
for operation 2.7V to 3.3V.
1. All voltages are referenced to ground.
2. Active mode current is measured with an 18MHz clock source driving XTAL1, VCC = RST = 3.3V, all other
pins disconnected.
3. Idle mode current is measured with an 18MHz clock source driving XTAL1, VCC = 3.3V, all other pins
disconnected.
4. Stop mode current measured with XTAL1 and RST grounded, VCC = 3.3V, all other pins disconnected.
5. When addressing external memory. This specification only applies to the first clock cycle following the
transition.
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NOTES FOR DS80C323 DC ELECTRICAL CHARACTERISTICS (continued)
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40°C
are guaranteed by design and are not production tested. Device operating range is 2.7V to 5.5V. DC electrical specifications are
for operation 2.7V to 3.3V.
6. RST = VCC. This condition mimics operation of pins in I/O mode.
7. During a 0-to-1 transition, a one-shot drives the ports hard for two clock cycles. This measurement reflects port
in transition mode.
8. Ports 1, 2, and 3 source transition current when being pulled down externally. It reaches its maximum at
approximately 2V.
9. VIN between ground and VCC - 0.3V. Not a high-impedance input. This port is a weak address latch because
Port 0 is dedicated as an address bus on the DS80C323. Peak current occurs near the input transition point of
the latch, approximately 2V.
10. Over the industrial temperature range, this specification has a maximum value of 200mA.
11. This is the current from an external circuit to hold a logic low level on an I/O pin while the corresponding port
latch bit is set to 1. This is only the current required to hold the low level; transitions from 1 to 0 on an I/O pin
will also have to overcome the transition current.
12. Device operating range is 2.7V to 5.5V, however device is tested to 2.5V to ensure proper operation at
minimum VRST.
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AC ELECTRICAL CHARACTERISTICS—DS80C323
18 MHz VARIABLE CLOCK
PARAMETER SYMBOL
MIN MAX MIN MAX
UNITS
External
Oscillator 0 18 0 18
Oscillator
Frequency External
Crystal
1/tCLCL
1 18 1 18
MHz
ALE Pulse Width tLHLL 68 1.5tCLCL-15 ns
Port 0 Address Valid
to ALE Low tAVLL 16 0.5tCLCL-11 ns
Address Hold After
ALE Low tLLAX1 6 (Note 5) 0.25tCLCL-8 (Note 5) ns
Address Hold After
ALE Low for MOVX WR tLLAX2 14 0.5tCLCL-13 ns
ALE Low to Valid
Instruction In tLLIV 93 2.5tCLCL-46 ns
ALE Low to PSEN Low tLLPL 4 0.25tCLCL-10 ns
PSEN Pulse Width tPLPH 118 2.25tCLCL-7 ns
PSEN Low to Valid
Instruction In tPLIV 87 2.25tCLCL-38 ns
Input Instruction Hold
After PSEN tPXIX 0 0 ns
Input Instruction Float
After PSEN tPXIZ 51 tCLCL-5 ns
Port 0 Address to Valid
Instruction In tAVIV1 128 3tCLCL-39 ns
Port 2 Address to Valid
Instruction In tAVIV2 139 3.5tCLCL-56 ns
PSEN Low to Address Float tPLAZ (Note 5) (Note 5) ns
NOTES FOR DS80C323 AC ELECTRICAL CHARACTERISTICS
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40°C
are guaranteed by design and are not production tested. AC electrical characteristics assume 50% duty cycle for the oscillator,
oscillator frequency > 16MHz, and are not 100% production tested, but are guaranteed by design.
1. All signals rated over operating temperature at 18MHz.
2. All signals characterized with load capacitance of 80pF except Port 0, ALE, PSEN , RD , and WR at 100pF.
Note that loading should be approximately equal for valid timing.
3. Interfacing to memory devices with float times (turn off times) over 35ns may cause contention. This will not
damage the parts, but will cause an increase in operating current.
4. Specifications assume a 50% duty cycle for the oscillator. Port 2 timing will change with the duty cycle
variations.
5. Address is held in a weak latch until over-driven by external memory.
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MOVX CHARACTERISTICS—DS80C323
VARIABLE CLOCK
PARAMETER SYMBOL
MIN MAX
UNITS STRETCH
2tCLCL-11 tMCS=0
RD Pulse Width tRLRH tMCS-11
ns tMCS>0
2tCLCL-11 tMCS=0
WR Pulse Width tWLWH tMCS-11
ns tMCS>0
2tCLCL-32 tMCS=0
RD Low to Valid Data In tRLDV t
MCS-36 ns tMCS>0
Data Hold After Read tRHDX 0 ns
t
CLCL-5 tMCS=0
Data Float After Read tRHDZ 2tCLCL-7 ns tMCS>0
2.5tCLCL-43 tMCS=0
ALE Low to Valid Data In tLLDV 1.5tCLCL-45+tMCS ns tMCS>0
3tCLCL-40 tMCS=0
Port 0 Address to Valid Data
In tAVDV1 2tCLCL-42+tMCS ns tMCS>0
3.5tCLCL-58 tMCS=0 Port 2 Address to Valid Data
In tAVDV2 2.5tCLCL-59+tMCS ns tMCS>0
0.5tCLCL-18 0.5tCLCL+7 tMCS=0
ALE Low to RD or WR
Low tLLWL 1.5tCLCL-11 1.5tCLCL+8 ns tMCS>0
tCLCL-10 tMCS=0
Port 0 Address Valid to RD
or WR Low tAVWL1 2tCLCL-10
ns tMCS>0
1.5tCLCL-27 tMCS=0
Port 2 Address Valid to RD
or WR Low tAVWL2 2.5tCLCL-25 ns tMCS>0
-14 tMCS=0
Data Valid to WR Transition tQVWX tCLCL-13 ns tMCS>0
tCLCL-15 tMCS=0
Data Hold After Write tWHQX 2tCLCL-13
ns tMCS>0
RD Low to Address Float tRLAZ (Note 5) ns
-1 14 tMCS=0
RD or WR High to
ALE High tWHLH tCLCL-5 tCLCL+16 ns tMCS>0
Note: tMCS is a time period related to the Stretch memory cycle selection. The following table shows the value of
tMCS for each Stretch selection.
M2 M1 M0 MOVX CYCLES tMCS
0 0 0 2 machine cycles 0
0 0 1 3 machine cycles (default) 4 tCLCL
0 1 0 4 machine cycles 8 tCLCL
0 1 1 5 machine cycles 12 tCLCL
1 0 0 6 machine cycles 16 tCLCL
1 0 1 7 machine cycles 20 tCLCL
1 1 0 8 machine cycles 24 tCLCL
1 1 1 9 machine cycles 28 tCLCL
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EXTERNAL CLOCK CHARACTERISTICS
PARAMETER SYMBOL MIN TYP MAX UNITS
Clock High Time tCHCX 10 ns
Clock Low Time tCLCX 10 ns
Clock Rise Time tCLCH 5 ns
Clock Fall Time tCHCL 5 ns
SERIAL PORT MODE 0 TIMING CHARACTERISTICS
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SM2 = 0;
12 clocks per cycle 12tCLCL
Serial Port Clock
Cycle Time tXLXL SM2 = 1;
4 clocks per cycle 4tCLCL
ns
SM2 = 0
12 clocks per cycle 10tCLCL
Output Data Setup to
Clock Rising Edge tQVXH SM2 = 1;
4 clocks per cycle 3tCLCL
ns
SM2 = 0
12 clocks per cycle 2tCLCL
Output Data Hold
from Clock Rising tXHQX SM2 = 1;
4 clocks per cycle t
CLCL
ns
SM2 = 0;
12 clocks per cycle t
CLCL
Input Data Hold After
Clock Rising tXHDX SM2 = 1;
4 clocks per cycle t
CLCL
ns
SM2 = 0;
12 clocks per cycle 11tCLCL
Clock Rising Edge to
Input Data Valid tXHDV SM2 = 1
4 clocks per cycle 2tCLCL
ns
EXPLANATION OF AC SYMBOLS
In an effort to remain compatible with the original 8051 family, this device specifies the same parameter as such
devices, using the same symbols. For completeness, the following is an explanation of the symbols.
t Time
A Address
C Clock
D Input data
H Logic level high
L Logic level low
I Instruction
P PSEN
Q Output data
R
RD signal
V Valid
W
WR signal
X No longer a valid logic level
Z Tri-state
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POWER-CYCLE TIMING CHARACTERISTICS
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Crystal Startup Time tCSU 1.8 ms 1
Power-On Reset Delay tPOR 65,536 tCLCL 2
NOTES FOR POWER CYCLE TIMING CHARACTERISTICS
1. Startup time for crystals varies with load capacitance and manufacturer. Time shown is for an 11.0592MHz
crystal manufactured by Fox crystal.
2. Reset delay is a synchronous counter of crystal oscillations after crystal startup. Counting begins when the
level on the XTAL1 input meets the VIH2 criteria. At 25MHz, this time is 2.62ms.
PROGRAM MEMORY READ CYCLE
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DATA MEMORY READ CYCLE
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DATA MEMORY WRITE CYCLE
DATA MEMORY WRITE WITH STRETCH = 1
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DATA MEMORY WRITE WITH STRETCH = 2
4-CYCLE DATA MEMORY WRITE
STRETCH VALUE = 2
EXTERNAL CLOCK DRIVE
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SERIAL PORT MODE 0 TIMING
SERIAL PORT 0 (SYNCHRONOUS MODE)
HIGH SPEED OPERATION SM2 = 1 ≥ TXD CLOCK = XTAL/4
SERIAL PORT 0 (SYNCHRONOUS MODE)
SM2 = 0 ≥ TXD CLOCK = XTAL/12
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POWER-CYCLE TIMING
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DATA SHEET REVISION SUMMARY
The following represent the key differences between the 070505 and 051804 version of the DS80C320/DS80C323 data
sheet. Please review this summary carefully.
1. Added Pb-free/RoHS-compliant part numbers to Ordering Information table.
2. Deleted the “A” from the IPC/JEDEC J-STD-020 specification in the Absolute Maximum Ratings.
The following represent the key differences between the 051804 and the 112299 version of the DS80C320/DS80C323 data
sheet. Please review this summary carefully.
1. Removed “Preliminary” status as a result of final characterization.
2. Added industrial temperature DS80C323 devices to ordering information.
3. Updated soldering temperature specification to reflect JEDEC standards.
4. Updated the following DS80C323 AC timing parameters with final characterization data: tLHLL, tLLAX1, tLLAX2, tLLAX2,
tLLIV, tLLPL, tPLIV, tAVIV1, tRLDV, tRHDZ, tLLDV, tAVDV1, tAVDV2, tLLWL, tAVWL1, tAVWL2, tQVWX, tWHQX, tWHLH.
5. Updated the following DS80C320 AC timing parameters with final characterization data: tWHQX, tLHLL, tLLAX2, tLLDV,
tAVDV1, tLLWL, tAVWL1, tAVWL2.
6. Added note advising the need to reset watchdog timer before setting the Stop bit.
7. Added note clarifying drive strength of P0, P2, ALE, PSEN.
8. Obsoleted DS80C320 25MHz AC timing tables; merged into 33MHz AC timing tables.
9. Corrected Serial Port Mode 0 Timing diagrams to show correct order of D6, D7.
The following represent the key differences between the 041896 and the 052799 version of the DS80C320 data sheet. Please
review this summary carefully.
1. Corrected VCC pin description to show DS80C323 operation at +3V.
2. Corrected Timed Access description to show three-cycle window.
3. Modified absolute Maximum Ratings for any pin relative to around, VCC relative to ground.
4. Changed minimum oscillator frequency to 1MHz when using external crystal.
5. Clarified that tPOR begins when XTAL1 reaches VIH2.
The following represent the key differences between the 103196 and the 041896 version of the DS80C320 data sheet. Please
review this summary carefully.
1. Updated DS80C320 25MHz AC Characteristics.
The following represent the key differences between the 041895 and the 031096 version of the DS80C320 data sheet. Please
review this summary carefully.
1. Remove Port 0, Port 2 from VOH1 specification (PCN B60802).
2. VOH1 test specification clarified (RST = VCC).
3. Add tAVWL2 marking to External Memory Read Cycle figure.
4. Correct TQFP drawing to read 44-pin TQFP.
5. Rotate page 1 TQFP illustration to match assembly specifications.
The following represent the key differences between the 031096 and the 052296 version of the DS80C320 data sheet. Please
review this summary carefully.
1. Added Data Sheet Revision Summary section.
The following represent the key differences between 05/23/96 and 05/22/96 version of the DS80C320 data sheet and
between 05/23/96 and 03/27/95 version of the DS80C323 data sheet. Please review this summary carefully.
DS80C320:
1. Add DS80C323 Characteristics.
2. Change DS80C320 VPFW specification from 4.5V to 4.55V (PCN E62802).
3. Update DS80C320 33MHz AC Characteristics.
DS80C323:
1. Delete Data Sheet. Contents moved to DS80C320/DS80C323.
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Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product.
No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products · Printed USA
are registered trademarks of Maxim Integrated Products, Inc., and Dallas Semiconductor Corporation.
DATA SHEET REVISION SUMMARY (continued)
The following represent the key differences between the 05/22/96 and the 10/21/97 version of the DS80C320 data sheet.
Please review this summary carefully.
DS80C320
1. Added note to clarify IIL specification.
2. Added note to clarify AC timing conditions.
3. Corrected erroneous tQVXL label on figure “Serial Port Mode 0 Timing” to read tQVXH.
4. Added note to prevent accidental corruption of Watchdog Timer count while changing counter length.
DS80C323
1. Added note to clarify IIL specification.
2. Remove port 2 from VOH1 specification, add port 3.
3. IOH for VOH3 specification changed from -3mA to -2mA.
4. Added note to clarify AC timing conditions.
