Datasheet
4D SYSTEMS DIABLO16 Processor
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DIABLO16 PROCESSOR
Serial Ports – TTL Level Serial 5.3.
The DIABLO16 Processor has three hardware
asynchronous serial ports that can be configured
on a variety of the processors GPIO pins. TX/RX0 is
dedicated and is fixed on to pins 33 (TX0) and 43
(RX0). All of the DIABLO16’s serial ports can be
used to communicate with external serial devices.
TX/RX0 are referred to as COM0, and is the only
one used for programming the DIABLO16 itself.
The primary features are:
Full-Duplex 8 bit data transmission and
reception.
Data format: 8 bits, No Parity, 1 Stop bit.
Independent Baud rates from 300 baud
up to 600K baud.
Single byte transmits and receives or a
fully buffered service. The buffered
service feature runs in the background
capturing and buffering serial data
without the user application having to
constantly poll any of the serial ports. This
frees up the application to service other
tasks.
A single byte serial transmission consists of the
start bit, 8-bits of data followed by the stop bit.
The start bit is always 0, while a stop bit is always
1. The LSB (Least Significant Bit, Bit 0) is sent out
first following the start bit. Figure below shows a
single byte transmission timing diagram.
COM0 is also the primary interface for 4DGL user
program downloads and chip configuration PmmC
programming. Once the compiled 4DGL
application program (EVE byte-code) is
downloaded and the user code starts executing,
the serial port is then available to the user
application. Refer to Section 7. In-Circuit-Serial-
Programming (ICSP) for more details on
PmmC/Firmware programming.
TX0 pin (Serial Transmit COM0):
Dedicated Asynchronous Serial port COM0
transmit pin, TX0. Connect this pin to external
serial device receive (Rx) signal. This pin is 5.0V
tolerant.
RX0 pin (Serial Receive COM0):
Dedicated Asynchronous Serial port COM0 receive
pin, RX0. Connect this pin to external serial device
transmit (Tx) signal. This pin is 5.0V tolerant.
TX1 pin (Serial Transmit COM1):
Asynchronous Serial port COM1 transmit pin, TX1.
Connect this pin to external serial device receive
(Rx) signal. This pin is 5.0V tolerant. This can be
configured to 1 of the GPIO pins, see table below.
RX1 pin (Serial Receive COM1):
Asynchronous Serial port COM1 receive pin, RX1.
Connect this pin to external serial device transmit
(Tx) signal. This pin is 5.0V tolerant. This can be
configured to 1 of the GPIO pins, see table below.
TX2 pin (Serial Transmit COM2):
Asynchronous Serial port COM2 transmit pin, TX2.
Connect this pin to external serial device receive
(Rx) signal. This pin is 5.0V tolerant. This can be
configured to 1 of the GPIO pins, see table below.
RX2 pin (Serial Receive COM2):
Asynchronous Serial port COM2 receive pin, RX2.
Connect this pin to external serial device transmit
(Tx) signal. This pin is 5.0V tolerant. This can be
configured to 1 of the GPIO pins, see table below.
TX3 pin (Serial Transmit COM3):
Asynchronous Serial port COM3 transmit pin, TX3.
Connect this pin to external serial device receive
(Rx) signal. This pin is 5.0V tolerant. This can be
configured to 1 of the GPIO pins, see table below.
RX3 pin (Serial Receive COM3):
Asynchronous Serial port COM3 receive pin, RX3.
Connect this pin to external serial device transmit
(Tx) signal. This pin is 5.0V tolerant. This can be
configured to 1 of the GPIO pins, see table below.