Picaso Processor
Datasheet
©
2017 4D Labs Semiconductors
Page 11 of 27
www.4dsystems.com.au
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
more details on PmmC/Firmware programming.
TX0 pin (Serial Transmit COM0):
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):
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.
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.
5.4.
Audio Interface
The exclusive audio support in the Picaso Processor
makes it better than its peers in the Graphics
processor range. PWM ensures better sound quality
with a volume range of 8 to 127. A simple instruction
empowers the user to execute the audio files. Audio
operation can be carried out simultaneously with the
execution of other necessary instructions.
For a complete list of audio commands please refer to
the separate document titled:
Picaso Internal Functions Manual
AUDIO pin (Audio PWM output):
External Amplifier Output pin. This pin provides a 16-
bit DAC/PWM audio output to use with an external
audio amplifier. Example circuit below provides a low
cost implementation. If unused then this pin must be
left open or floating.
Optional Power Audio Circuit
AUDENB pin (Audio Enable output):
External Amplifier enable pin. This pin provides
ON/OFF amplifier control. If unused then this pin must
be left open or floating.
LOW: Enable external Audio amplifier.
HIGH: Disable external Audio amplifier.