Xycom XVME 200, Manual

Page: 33 / 57

XVME-200/290 Manual
December, 1987
1 1
7 6 5 4 3 2
1 0
PC7/TIACK PC6/PIACK
PIRQ TINTEN PC3/TOUT PCZ/TIN PORT B PORT A
Input
Input output output output Input output output
Figure 3-3. Port C/Alternate Function Signal Definitions
The following is a brief explanation of each PORT C bit:
Bits
0 and 1 are used to control the direction of the 8-bit data
transceivers which are used to buffer the Port A and Port B data
lines.
After start-up or reset, these bits should be programmed as
outputs.
Bit
.
Bit
l
Bit
2 is used as a timer input line if the 68230 timer function is being
utilized.
If the timer function is not being used, this bit could be
employed as a general purpose input line.
3 is used as a timer output line if the 68230 timer function is being
utilized. If the timer function is not being used, this bit could be
employed as a general purpose output line.
4 is used as a timer interrupt enable line of the 68230 timer
function is being utilized.
This bit can only be used for the timer
interrupt function.
.
Bit
5 is used as a port interrupt request line if the 68230 port
interrupts are enabled. This bit can only be used for the port
interrupt function.
l
Bit
6 is used as a port interrupt acknowledge line if the 68230 port
interrupts are enabled.
This bit can onlv be used for the port
interrupt function.
.
Bit
7 is used as a timer interrupt acknowledge line if the 68230 timer
functions are being utilized.
This bit can only be used for the
timer interrupt function.
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