TIMER/EVENT COUNTER BEHAVIOR DURING WAIT and STOP
MOTOROLA
DSP56002 TIMER AND EVENT COUNTER
7 - 15
contained by the TCR, and the entire process is repeated until the timer is disabled
(TE=0). The INV bit determines whether 0-to-1 transitions (INV=0) or 1-to-0 transitions
(INV=1) will decrement the counter. Figure 7-14 illustrates Timer Mode 7 when INV=0,
and Figure 7-15 illustrates Timer Mode 7 when INV=1.
7.6
TIMER/EVENT COUNTER BEHAVIOR DURING WAIT and STOP
During the execution of the WAIT instruction, the timer clocks are active and the timer ac-
tivity continues undisturbed. If the timer interrupt is enabled when the final event occurs,
an interrupt will be generated and serviced.
It is recommended that the timer be disabled before executing the STOP instruction be-
cause during the execution of the STOP instruction, the timer clocks are disabled and the
timer activity will be stopped. If, for example, the TIO pin is used as input, the changes
TE
TCR
Periodic Event (First Event)
Clock
N
Counter
N
N+1
N+2
Interrupt
TIO
Periodic Event
M-1
M
M
M+1
M+2
N + 1
Figure 7-10 Period Measurement Mode (INV=0)
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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