mc68hc908mr32 Freescale Semiconductor, Inc, mc68hc908mr32 Datasheet - Page 125

• Manufacturer Part Number: mc68hc908mr32
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

12.4.2 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
is less than or 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
Freescale Semiconductor
12-3.
The terms “active” and “inactive” refer to the asserted and negated states
of the PWM signals and should not be confused with the high-impedance
state of the PWM pins.
PWMVALxH:PWMVALxL
COUNTER
Table 12-3. PWM Data Overflow and Underflow Conditions
UP-ONLY
$0000–$0FFF
$1000–$7FFF
$8000–$FFFF
PWM VALUE = 2
MODULUS = 3
PWM
PWMF SET
LDOK = 1
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Figure 12-11. Edge-Aligned Modulus Loading
PWM VALUE = 2
MODULUS = 4
PWMF SET
LDOK = 1
LDFQ1:LDFQ0 = 00 (RELOAD EVERY CYCLE)
Condition
Underflow
Overflow
NOTE
Normal
PWM VALUE = 2
Figure 12-4
MODULUS = 2
PWMF SET
LDOK = 1
Per register contents
and
PWM Value Used
PWM VALUE = 2
MODULUS = 1
PWMF SET
LDOK = 0
Figure
$FFF
$000
12-5, if the PWM value
PWM Generators
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