s908gz60cfa Freescale Semiconductor, Inc, s908gz60cfa Datasheet - Page 265

• Manufacturer Part Number: s908gz60cfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

18.3.3 Output Compare
With the output compare function, the TIM1 can generate a periodic pulse with a programmable polarity,
duration, and frequency. When the counter reaches the value in the registers of an output compare
channel, the TIM1 can set, clear, or toggle the channel pin. Output compares can generate TIM1 CPU
interrupt requests.
18.3.3.1 Unbuffered Output Compare
Any output compare channel can generate unbuffered output compare pulses as described in
Output
the new value over the old value currently in the TIM1 channel registers.
An unsynchronized write to the TIM1 channel registers to change an output compare value could cause
incorrect operation for up to two counter overflow periods. For example, writing a new value before the
counter reaches the old value but after the counter reaches the new value prevents any compare during
that counter overflow period. Also, using a TIM1 overflow interrupt routine to write a new, smaller output
compare value may cause the compare to be missed. The TIM1 may pass the new value before it is
written.
Freescale Semiconductor
BUS CLOCK
INTERNAL
Compare. The pulses are unbuffered because changing the output compare value requires writing
TSTOP
TRST
16-BIT COMPARATOR
16-BIT COMPARATOR
16-BIT COMPARATOR
T1MODH:T1MODL
16-BIT COUNTER
T1CH0H:T1CH0L
T1CH1H:T1CH1L
16-BIT LATCH
16-BIT LATCH
CHANNEL 0
CHANNEL 1
MC68HC908GZ60 • MC68HC908GZ48 • MC68HC908GZ32 Data Sheet, Rev. 6
PRESCALER
ELS0B
ELS1B
Figure 18-2. TIM1 Block Diagram
MS0A
MS1A
PS2
ELS0A
ELS1A
PRESCALER SELECT
PS1
CH0F
MS0B
CH1F
PS0
CH0MAX
CH1MAX
CH0IE
CH1IE
TOV0
TOV1
TOIE
TOF
INTERRUPT
INTERRUPT
INTERRUPT
LOGIC
LOGIC
LOGIC
LOGIC
LOGIC
PORT
PORT
Functional Description
PTD4/T1CH0
PTD5/T1CH1
18.3.3
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