mc68hc05pv8a Freescale Semiconductor, Inc, mc68hc05pv8a Datasheet - Page 150

• Manufacturer Part Number: mc68hc05pv8a
• Description: Mc68hc05pv8a Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Technical Data
11.4 Registers
11.4.1 PWM Control Register
Technical Data
Associated with the PWM system, there are a PWM data register, a
PWM period register and a PWM control register. These registers can
be written to and read at any time. Writing to the data or the period
register takes effect when the whole PWM system is started by switching
on the PWMON bit or when a conversion cycle is complete. After reset
the user should write to the prescaler bits prior to enabling the PWM
system. This prevents an erroneous duty cycle from being driven.
PWMON – PWM Module On
POL – PWM Polarity
CYCLE – PWM Cycle Completed
$002D
Reset:
Read:
Write:
When set, this bit makes the active PWM pulse high. When cleared,
the output is active low (e.g. $00 in the data register yields an all high
signal for POLA = 0). The programmed polarity bit is copied into a
shadow polarity bit when the PWM data register is written. At the end
of the current conversion, the shadow polarity bit takes effect.
This bit indicates the completion (reload of PWM data and period) of
a PWM cycle. This flag is cleared by writing a 1 to the bit position.
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = PWM module operating
0 = PWM module stopped
1 = PWM polarity active high
0 = PWM polarity active low
1 = PWM registers were reloaded after last flag clear
0 = PWM registers were not reloaded after last flag clear
PWMON
Bit 7
0
Figure 11-4 PWM Control Register (PWMCR)
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Pulse Width Modulator
POL
6
0
5
0
0
CYCLE
4
0
PRA3
3
0
MC68HC(8)05PV8/A — Rev. 1.9
PRA2
2
0
PRA1
1
0
PRA0
Bit 0
0