4d Systems 3.2" TFT Intelligent Display SK-32PTU SK-32PTU Datenbogen

Produktcode

SK-32PTU

4D SYSTEMS µLCD-32PTU

4. Hardware Interface - Pins

The μLCD-32PTU provides both a hardware and
software interface. This section describes in detail
the hardware interface pins of the device.

Serial Ports - COM0, COM1 UARTS

The μLCD-32PTU has two dedicated hardware
Asynchronous Serial ports that can communicate
with external serial devices. These are referred to as
the COM0 and the COM1 serial ports.
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 5. ‘Firmware / PmmC Programming’ for
more details on this subject.

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.

General Purpose I/O

There are 13 general purpose Input/Output (GPIO)
pins  available  to  the  user.  These  are  grouped  as
IO1..IO5  (Note  for  IO1,  IO2  and  IO3  below)  and
BUS0..BUS7. Power-Up Reset default is all INPUTS.

The  5  I/O  pins  (IO1..IO5),  provide  flexibility  of
individual  bit  operations  while  the  8  pins
(BUS0..BUS7),  known  as  GPIO  BUS,  serve
collectively  for  byte  wise  operations.  The  IO4  and
IO5 also act as strobing signals to control the GPIO
Bus. GPIO Bus can be read or written by strobing a
low  pulse  (50ns  duration  or  greater)  the
IO4/BUS_RD  or  IO5/BUS_WR  for  read  or  write
respectively.  For  detailed  usage  refer  to  the
separate document titled:
“PICASO-4DGL-Internal-Functions.pdf”

IO1-IO5 pins (excluding IO3) (2 x GPIO pins):
General  purpose  I/O  pins.  Each  pin  can  be
individually set for INPUT or an OUTPUT.

IO1 pin (Frame Mark pin):
The IO1 pin has 2 functions. It can be used as a GPIO
pin  but  can  also  be  used  to  detect  the  start  of  a
Frame. When used as a GPIO pin, simply connect an
Input/Output  to  the  IO1  pin  on  the  H1  header.
When using IO1 for Frame Mark, simply leave the
IO1 pin on the H1 header disconnected, and read
the status of IO1 as an Input.

IO2 pin (Lithium Battery Status pin):
The IO2 pin has 2 functions. It can be used as a GPIO
pin but can also be used to tell when the  Lithium
battery has reached a low level (3.7V) and needs to