CALIBRE
INTRODUCTION
1.1.General Introduction
The Parallel I2C Communications Adapter is designed to connect to any IBM PC compatible parallel port. It is based on the Philips PCF8584 bus controller, it features full I2C
1.2.Packing List
Your Parallel I2C Communications Adapter is supplied with the following items:-
A.I2C CD - ROM
B.The PICA93LV unit (the actual adapter)
C.A cable set
1 25 way parallel cable
2 6 pin mini DIN male
3 5 pin DIN female
4 6 pin mini DIN female
1.3.. Configuring the Adapter
NOTE: MANY COMPONENTS ON THE ADAPTER CARD ARE STATIC SENSITIVE. OBSERVE NORMAL STATIC SENSITIVE PRECAUTIONS WHEN HANDLING THE CARD!
The adapter is supplied in a standard configuration which should suit most applications. However, the bus termination and protection are link selectable. Read the following section to change the configuration.
The standard configuration is bus termination and protection off
1.4.Bus Termination and Protection
Normally the system to which the Parallel I2C Communications Adapter is to be connected should already have master pull up resistors fitted to the SCL and SDA lines. If this is not the case, LK6 and LK7 can be used to connect 4.7K pull up resistors to the 5V supply on these lines.
The standard configuration is with these resistors disconnected.
The SCL and SDA lines are protected by 100R series resistors before exiting the adapter via the 9 way "D" socket. Upstream of the series resistors, the SCL and SDA pins on the PCF8584 are pulled up with high value resistors (10K). These ensure that the I2C Bus is in a defined state even if no other devices are connected.
LK4 and LK5 connect optional protection diodes to the SCL and SDA lines. When selected, these lines are clamped to the 0V and + 5V lines giving protection against transients. If these diodes are connected, the external I2C system will not function if the adapter is connected but not powered up.
The standard configuration is with these diodes disconnected.
Issue 1.3 | Page 1 |
22/07/99
