Datasheet

385

6120F–ATARM–03-Oct-06

AT91SAM7X512/256/128 Preliminary

Figure 32-2. Clock Selection

32.5.1.3 Clock Control

The clock of each counter can be controlled in two different ways: it can be enabled/disabled

and started/stopped. See Figure 32-3.

• The clock can be enabled or disabled by the user with the CLKEN and the CLKDIS

commands in the Control Register. In Capture Mode it can be disabled by an RB load event if

LDBDIS is set to 1 in TC_CMR. In Waveform Mode, it can be disabled by an RC Compare

event if CPCDIS is set to 1 in TC_CMR. When disabled, the start or the stop actions have no

effect: only a CLKEN command in the Control Register can re-enable the clock. When the

clock is enabled, the CLKSTA bit is set in the Status Register.

• The clock can also be started or stopped: a trigger (software, synchro, external or compare)

always starts the clock. The clock can be stopped by an RB load event in Capture Mode

(LDBSTOP = 1 in TC_CMR) or a RC compare event in Waveform Mode (CPCSTOP = 1 in

TC_CMR). The start and the stop commands have effect only if the clock is enabled.

TIMER_CLOCK1

TIMER_CLOCK2

TIMER_CLOCK3

TIMER_CLOCK4

TIMER_CLOCK5

XC0

XC1

XC2

TCCLKS

CLKI

BURST

Selected

Clock