User manual

D. Digital I/O Registers and Connections.
Four digital TTL inputs and four digital TTL outputs are
provided by the modem status and modem control registers of
UARTs U4 and U5. These I/O are connected to the card via J1
using a 16-pin flat cable connector. Register designations and
connector J1 pin assignments are given in Table 2. The inputs
and outputs on connector J1 are the inverted values of those
read or written in the modem status and control registers. For
example, a 1 written to OUT1 of U4 results in a 0 at J1-1
(OUT1_BUFFERED). Similarly, a 1 applied to J1-9 (IN1) results
in a 0 being read in CTS of U4.
Table 2. Digital I/O Register Designations and J1 Pin Assignments.
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
Name I/O UART Register J1 Pin*
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
OUT1_BUFFERED Output U4 (Primary) OUT1 1
OUT2 Output U4 (Primary) OUT2 3
OUT3 Output U5 (Secondary) OUT1 5
OUT4 Output U5 (Secondary) OUT2 7
IN1 Input U4 (Primary) CTS 9
IN2 Input U4 (Primary) DSR 11
IN3 Input U5 (Secondary) CTS 13
IN4 Input U5 (Secondary) DSR 15
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
* J1 even numbered pins 2 thru 16 are ground.
Page 10 MSI-P602 User Manual