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are trademarks of their respective owners.
Copyright 1999-2007 DCD – Digital Core Design. All Rights Reserved.
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http://www.DigitalCoreDesign.com
http://www.dcd.pl
SCI - The SCI is a full-duplex UART type
asynchronous system, using standard non
return to zero (NRZ) format : 1 start bit, 8 or 9
data bits and a 1 stop bit. The DF6805 resyn-
chronizes the receiver bit clock on all one to
zero transitions in the bit stream. Therefore
differences in baud rate between the sending
device and the SCI are not as likely to cause
reception errors. Three logic samples are
taken near the middle of data bit time, and
majority logic decides the sense for the bit.
For the start and stop bits seven logic sam-
ples are taken. Even if noise causes one of
these samples to be incorrect, the bit will still
be received correctly. The receiver also has
the ability to enter a temporary standby mode
(called receiver wakeup) to ignore messages
intended for a different receiver. Logic auto-
matically wakes up the receiver in time to see
the first character of the next message. This
wakeup feature greatly reduces CPU over-
head in multi-drop SCI networks. The SCI
transmitter can produce queued characters of
idle (whole characters of all logic 1) and break
(whole characters of all logic 0). In addition to
the usual transmit data register empty (TDRE)
status flag, this SCI also provides a transmit
complete (TC) indication that can be used in
applications with a modem.
DoCDTM - Debug Unit – it’s a real-time hard-
ware debugger provides debugging capability
of a whole SoC system. In contrast to other
on-chip debuggers DoCD™ provides non-
intrusive debugging of running application. It
can halt, run, step into or skip an instruction,
read/write any contents of microcontroller in-
cluding all registers, internal, external, pro-
gram memories, all SFRs including user de-
fined peripherals. Hardware breakpoints can
be set and controlled on program memory,
internal and external data memories, as well
as on SFRs. Hardware breakpoint is executed
if any write/read occurred at particular address
with certain data pattern or without pattern.
The DoCDTM system includes three-wire inter-
face and complete set of tools to communi-
cate and work with core in real time debug-
ging. It is built as scalable unit and some fea-
tures can be turned off to save silicon and
reduce power consumption. A special care on
power consumption has been taken, and
when debugger is not used it is automatically
switched in power save mode. Finally whole
debugger is turned off when debug option is
no longer used.
OPTIONAL
PERIPHERALS
There are also available an optional pe-
ripherals, not included in presented DF6805
Microcontroller Core. The optional peripherals,
can be implemented in microcontroller core
upon customer request.
SPI – Master and Slave Serial Peripheral
Interface
Supports speeds up ¼ of system clock
Mode fault error
Write collision error
Software selectable polarity and phase of se-
rial clock SCK
System errors detection
Allows operation from a wide range of system
clock frequencies (build-in 5-bit timer)
Interrupt generation
I2C bus controller - Master
7-bit and 10-bit addressing modes
NORMAL, FAST, HIGH speeds
Multi-master systems supported
Clock arbitration and synchroni zation
User defined timings on I2C lines
Wide range of syst em clock frequ encies
Interrupt generation
I2C bus controller - Slave
NORMAL speed 100 kbs
FAST speed 400 kbs
HIGH speed 3400 kbs
Wide range of syst em clock frequ encies
User defined data setup time on I2C lines
Interrupt generation
PWM – Pulse Width Modulation Timer
Fixed-Point arithmetic coprocessor
Floating-Point arithmetic coprocessor
IEEE-754 standard single precision
Floating-Point math coprocessor - IEEE-
754 standard single precision real, word
and short integers