mc68hc908mr8 Freescale Semiconductor, Inc, mc68hc908mr8 Datasheet - Page 146

• Manufacturer Part Number: mc68hc908mr8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Pulse-Width Modulator for Motor Control
9.4 Timebase
9.4.1 Resolution
Technical Data
146
This subsection provides for a discussion of the timebase.
In center-aligned mode, a 12-bit up/down counter is used to create the
PWM period. Therefore, the PWM resolution in center-aligned mode is
two clocks (highest resolution is 250 ns @ f
Figure
register to determine its maximum count. The PWM period will equal:
For edge-aligned mode, a 12-bit up-only counter is used to create the
PWM period. Therefore, the PWM resolution in edge-aligned mode is
one clock (highest resolution is 125 ns @ f
Figure
maximum count. The PWM period will equal:
Center-aligned operation versus edge-aligned operation is determined
by the option EDGE. See
Pulse-Width Modulator for Motor Control (PWMMC)
9-3. The up/down counter uses the value in the timer modulus
9-4. Again, the timer modulus register is used to determine the
(timer modulus) x (PWM clock period) x 2
(timer modulus) x (PWM clock period)
5.4 CONFIG
Bits.
OP
OP
= 8 MHz) as shown in
= 8 MHz) as shown in
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor