mc68hc908lb8 Freescale Semiconductor, Inc, mc68hc908lb8 Datasheet - Page 148

• Manufacturer Part Number: mc68hc908lb8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Pulse Width Modulator with Fault Input (PWM)
15.4.2 PWM Data Overflow and Underflow Conditions
The PWM value registers are 16-bit registers. Although the counter is only 12 bits, the user may write a
16-bit signed value to a PWM value register. As shown in
equal to zero, the PWM will be inactive for the entire period. Conversely, if the PWM value is greater than
or equal to the timer modulus, the PWM will be active for the entire period. Refer to
Table
148
15-3.
direction register. In order to read the states of the pins, the data direction
register bit must be a 0.
COUNTER
UP-ONLY
COUNTER
PWM VALUE = 1
UP-ONLY
MODULUS = 3
PWM VALUE = 2
PWMF SET
LDOK = 1
MODULUS = 3
PWM
PWM
PWMF SET
LDOK = 1
Figure 15-7. Edge-Aligned PWM Value Loading
Figure 15-8. Edge-Aligned Modulus Loading
PWM VALUE = 2
MODULUS = 3
PWMF SET
LDOK = 0
MC68HC908LB8 Data Sheet, Rev. 1
LDFQ1:LDFQ0 = 00 (RELOAD EVERY CYCLE)
PWM VALUE = 2
MODULUS = 4
PWMF SET
LDOK = 1
PWM VALUE = 2
MODULUS = 3
LDFQ1:LDFQ0 = 00 (RELOAD EVERY CYCLE)
PWMF SET
LDOK = 1
PWM VALUE = 1
MODULUS = 3
PWM VALUE = 2
Figure
MODULUS = 2
PWMF SET
LDOK = 0
PWMF SET
LDOK = 1
15-4, if the PWM value is less than or
PWM VALUE = 1
MODULUS = 3
PWM VALUE = 2
PWMF SET
MODULUS = 1
LDOK = 0
PWMF SET
LDOK = 0
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