SAM7S256_14 Datasheet, PDF (459/775 Pages) ATMEL Corporation – ARM-based Flash MCU

33.5.11.3 WAVSEL = 01
When WAVSEL = 01, the value of TC_CV is incremented from 0 to 0xFFFF. Once 0xFFFF is reached, the value of
TC_CV is decremented to 0, then re-incremented to 0xFFFF and so on. See Figure 33-11.
A trigger such as an external event or a software trigger can modify TC_CV at any time. If a trigger 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 33-12.
RC Compare cannot be programmed to generate a trigger in this configuration.
At the same time, RC Compare can stop the counter clock (CPCSTOP = 1) and/or disable the counter clock
(CPCDIS = 1).
Figure 33-11. WAVSEL = 01 Without Trigger
Counter Value
Counter decremented by compare match with 0xFFFF
0xFFFF
R_C
R_B
R_A
Waveform Examples
TIOB
Time
TIOA
Figure 33-12. WAVSEL = 01 With Trigger
Counter Value
0xFFFF
R_C
Counter cleared by compare match with RC _{Counter cleared by trigger}
R_B
R_A
Waveform Examples
TIOB
Time
TIOA
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
459