s908gr32ag3vfa Freescale Semiconductor, Inc, s908gr32ag3vfa Datasheet - Page 258

• Manufacturer Part Number: s908gr32ag3vfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Timer Interface Module (TIM2)
CHxMAX — Channel x Maximum Duty Cycle Bit
18.8.5 TIM2 Channel Registers
These read/write registers contain the captured TIM2 counter value of the input capture function or the
output compare value of the output compare function. The state of the TIM2 channel registers after reset
is unknown.
In input capture mode (MSxB:MSxA = 0:0), reading the high byte of the TIM2 channel x registers
(T2CHxH) inhibits input captures until the low byte (T2CHxL) is read.
In output compare mode (MSxB:MSxA ≠ 0:0), writing to the high byte of the TIM2 channel x registers
(T2CHxH) inhibits output compares until the low byte (T2CHxL) is written.
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When the TOVx bit is at a 1 and clear output on compare is selected, setting the CHxMAX bit forces
the duty cycle of buffered and unbuffered PWM signals to 100%. As
bit takes effect in the cycle after it is set or cleared. The output stays at 100% duty cycle level until the
cycle after CHxMAX is cleared.
Figure 18-10. TIM2 Channel Registers (T2CH0H/L:T2CH5H/L) (Sheet 1 of 3)
PTDx/T2CHx
Address: $0031
Address: $0032
The 100% PWM duty cycle is defined as a continuous high level if the PWM
polarity is 1 and a continuous low level if the PWM polarity is 0. Conversely,
a 0% PWM duty cycle is defined as a continuous low level if the PWM
polarity is 1 and a continuous high level if the PWM polarity is 0.
CHxMAX
Reset:
Reset:
Read:
Read:
Write:
Write:
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
OVERFLOW
Bit 15
Bit 7
Bit 7
Bit 7
COMPARE
T2CH0H
T2CH0L
PERIOD
OUTPUT
Bit 14
Bit 6
6
6
Figure 18-9. CHxMAX Latency
OVERFLOW
Bit 13
Bit 5
5
5
COMPARE
OUTPUT
Indeterminate after reset
Indeterminate after reset
NOTE
Bit 12
Bit 4
OVERFLOW
4
4
Bit 11
Bit 3
COMPARE
OUTPUT
3
3
OVERFLOW
Bit 10
Bit 2
2
2
Figure 18-9
COMPARE
OUTPUT
Bit 9
Bit 1
1
1
OVERFLOW
shows, the CHxMAX
Freescale Semiconductor
Bit 0
Bit 8
Bit 0
Bit 0