- 1 -
In the absence of confirmation by device specification sheets, SHARP takes no responsibility for any defects that may occur in equipment using any SHARP devices shown in catalogs, data books,
etc. Contact SHARP in order to obtain the latest device specification sheets before using any SHARP device.
SM3518
DESCRIPTION
The SM3518 is a CMOS 4-bit single-chip micro-
computer for databank incorporating data memory
RAM, LCD driver (the output is adjustable in 16
steps for various contrast), key/switch input circuit,
8-bit parallel I/O port, 2 output ports and buzzer
output circuit. The chip also has memory expansion
controlling feature. One of two ports contains spe-
cial output circuit for infrared (IR) communication.
By connecting an external crystal, a 1Hz timer is
made possible for easier clock function.
FEATURES
• ROM capacity :
Program ROM 12 k x 23 bits
Character ROM 6 x 8 x 256 bits
Constant ROM 1 k x 4 bits
• RAM capacity :
Working RAM 256 x 4 bits
Display RAM 74 x 16 bits
Data RAM 3 k x 8 bits
• Memory expansion (external) : 1M x 8 bits x 3
• LCD display : 74 - segment x 16 - common
• I/O ports :
Parallel I/O 8 bits
Input 2 bits
Output 2 bits
Buzzer output 1 bit (4 kHz)
Key input 6 bits
• Standby release : 2 events (2 Hz signal, key input)
• Built-in oscillator :
• Instruction cycle time : 3 µs
• Operating temperature : –10 to +60 °C
• Supply voltage : 2.5 to 5.5 V
• Package : 128-pin QFP (QFP128-P-2828)
[Test Sample only]
SM3518 4-Bit Single-Chip Microcomputer
(For Data Bank Use)
System clock (built-in CR oscillator) 1 MHz
(external ceramic resonator) 1 MHz
Timer (built-in CR oscillator) 32.8 kHz
(external crystal)
32.768 kHz
SM3518
- 2 -
SYSTEM COMFIGURATION EXAMPLE
Key matrix
Expand
memory
1 M-byte x 3
S1-S8
S9-S28
S67-S74
(MAX. 112-key)
S1-S74
CE1-CE3
KI1-KI7
DIO1-DIO8
RW
CE
KI8VCC TEST CCI CCO RESET CXI CXOBZ
H1-H16
EO2
VH
V1
V2
V3
V4
Infrared signal
for IR communication
VCC
VCC Buzzer
VCC
SM3518
RESET
key
5V
SW
(HIGH END DATA BANK)
Common signal
Segment signal
+
–
VCC
SM3518
- 3 -
± 0.3
28.0
TYP.
0.8 0.15
± 0.05
65
± 0.1
0.38
± 0.2
3.45
± 0.1
1
97
96
32
33
64
128
(1.6)
31.2
± 0.5
(1.6)
28.0
31.2
± 0.3
± 0.5
(1.6) (1.6)
0.1
1.65
(29.6)
0.15
0.15
M
Package
base plane
128 QFP (QFP128-P-2828)
