8XC196MC, MD, MH USER’S MANUAL
11-22
11.5.4 Programming the Compare-only Channels
To program a compare event, you must first write to the COMPx_CON register (Figure 11-11) to
configure the compare-only channel and then load the event time into COMPx_TIME.
COMPx_CON has the same bits and settings as EPAx_CON. COMPx_TIME is functionally iden-
tical to EPAx_TIME.
COMP
x
_CON
x
= 0–3 (8XC196MC, MH)
x
= 0–5 (8XC196MD)
Address:
Reset State:
See Table 11-3 on
page 11-3
00H
The EPA compare control (COMP
x
_CON) registers determine the function of the EPA compare
channels.
7 0
x
= 0, 2, 4 TB CE M1 M0 RE WGR ROT RT
7 0
x
= 1, 3, 5 TB CE M1 M0 RE AD ROT RT
7 TB Time Base Select
Specifies the reference timer.
0 = timer 1 is the reference timer and timer 2 is the opposite timer
1 = timer 2 is the reference timer and timer 1 is the opposite timer
A compare event (start of an A/D conversion; clearing, setting, or toggling
an output pin; and/or resetting either timer) occurs when the reference
timer matches the time programmed in the event-time register.
6 CE Compare Enable
This bit enables the compare function.
0 = compare function disabled
1 = compare function enabled
5:4 M1:0 EPA Mode Select
Specifies the type of compare event.
M1 M0
0 0 no output
0 1 clear output pin
1 0 set output pin
1 1 toggle output pin
3 RE Re-enable
Allows a compare event to continue to execute each time the event-time
register (COMP
x
_TIME) matches the reference timer rather than only
upon the first time match.
0 = compare function will drive the output only once
1 = compare function always enabled
Figure 11-11. EPA Compare Control (COMP
x
_CON) Registers