Datasheet

395
6120F–ATARM–03-Oct-06
AT91SAM7X512/256/128 Preliminary
A trigger such as an external event or a software trigger can modify TC_CV at any time. If a trig-
ger occurs while TC_CV is incrementing, TC_CV then decrements. If a trigger is received while
TC_CV is decrementing, TC_CV then increments. See Figure 32-13.
RC Compare can stop the counter clock (CPCSTOP = 1) and/or disable the counter clock (CPC-
DIS = 1).
Figure 32-12. WAVSEL = 11 Without Trigger
Figure 32-13. WAVSEL = 11 With Trigger
32.5.3.6 External Event/Trigger Conditions
An external event can be programmed to be detected on one of the clock sources (XC0, XC1,
XC2) or TIOB. The external event selected can then be used as a trigger.
Time
Counter Value
R
C
R
B
R
A
TIOB
TIOA
Counter decremented by compare match with RC
0xFFFF
Waveform Examples
Time
Counter Value
TIOB
TIOA
Counter decremented by compare match with RC
0xFFFF
Waveform Examples
Counter decremented
by trigger
Counter incremented
by trigger
R
C
R
B
R
A