M87222NF-D Development System questions
10.5. MBDEV-A - INTX, SYNC and DCD pins
* The INTX pin is connected to pin RB1 on the 18F8722 MCU.
With this connection, a circuit on the prototype area can request a CPU interrupt.
* The SYNC pin is connected to RA4 on the 18F8722 MCU.
When using the GS3 Software this pin will have a 1PPS signal.
Note: This pin has 1 4.7K pullup resistor connected to it.
* The DCD pin is connected (via the I/O cables) to pin 1of the DB9 serial port on the main
board.
Some systems use this pin to provide a 1PPS timing signal over the RS232 port.
Note: The RS232 level connection is not made to the DCD pin. It is up to the user to do
this on the prototyping area. In other words, if you need a RS232 level signal on the DCD
pin of the serial port, then you must use a TTL-to-RS232 level converter chip.
