Open Access
Circuit Descriptions
3-15
ARM Development Board (ARM7TDMI Version)
Hardware Reference Guide
ARM DUI 0017C
3.2.10 Serial and Parallel Ports
The serial and parallel ports schematic is shown in
A.12 Serial and Parallel Ports
on
page A-13.
The serial and parallel I/O subsystem is based around an ST16C552 device. This is a dual
asynchronous receiver and transmitter with 16-byte transmit and receive FIFO and a
bi-directional Centronics type parallel printer port. This device is pin and functionally
compatible with the VL16C552 and the WD16C552. In order to program the device you are
advised to obtain a data sheet for one of these devices. Please contact ARM if you have any
problems obtaining the datasheet.
The XR16C552 (U21) drives two serial ports (A and B) through two RS232 level shifters
(U22 and U23). To connect to the serial ports you will need a cable that terminates in a 9-pin
D socket. The pinout is compatible with a standard PC serial port and is shown
Table 3-8:
Serial port pinout
:
The ST16C552 also drives a Centronics-type parallel port. To connect to the parallel port
you will need a cable that terminates in a 25-way D plug. The pinout is compatible with a
standard PC parallel port and is shown in
Table 3-9: Parallel port pinout
on page 3-16.
Pin Function Direction
1 DCD in
2RxDin
3 TxD out
4DTRout
5 GND power
6DSRin
7 RTS out
8CTSin
9 RI in
Table 3-8: Serial port pinout
hrg.book Page 15 Wednesday, July 22, 1998 9:18 AM
To Next Page
Loading...
