9-4
BajaPPC-750: Counter/Timers
9.2.5 Mode Register
The timer Mode Register, CTMR, is used to initialize and start the timer. The for-
mat of this register is described in the following table.
DH3
DH4
DH5
DH6
DH7
StrStp
IntrEn
OvFlEn
CTMode
Enable
Register Map 9-2. Counter/Timer Mode, CTMR
StrStp
The start/stop timer bit starts the timer when set and stops the timer
when cleared. Use this feature when trying to read the current count
from the CTCR. The start/stop timer bit is initially set and cleared
through this register, however it may also be cleared by the counter. This
is possible when the timer is configured as a timer and has reached ter-
minal count, or when the timer is configured to stop on overflow and
overflow has occurred.
IntrEn
When the interrupt enable bit is set, it allows the interrupt pending sta-
tus to generate interrupt requests.
OvFlEn
When the overflow enable bit is set, the counter stops if a terminal count
is reached and the previous interrupt has not been serviced. If this bit is
cleared the counter continues regardless of the error condition.
CTMode
The counter/timer mode bit determines which of the modes the timer
operates in. When cleared the counter/timer operates in timer mode,
which counts down to zero once and then stops. When set the counter/
timer operates in counter mode, which continually counts down to zero
and reloads.
Enable
The enable bit acts as a general purpose reset for the counter/timer.
When set the timer can operate normally. When cleared the timer is
stopped and reloaded, and the status is cleared.
Содержание BajaPPC-750
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