MC908MR16CBE Datasheet, PDF (143/282 Pages) Freescale Semiconductor, Inc – The following revision history table summarizes changes contained in this document.

PWM Operation in Wait Mode
12.8 PWM Operation in Wait Mode
When the microcontroller is put in low-power wait mode via the WAIT instruction, all clocks to the PWM
module will continue to run. If an interrupt is issued from the PWM module (via a reload or a fault), the
microcontroller will exit wait mode.
Clearing the PWMEN bit before entering wait mode will reduce power consumption in wait mode because
the counter, prescaler divider, and LDFQ divider will no longer be clocked. In addition, power will be
reduced because the PWMs will no longer toggle.
12.9 Control Logic Block
This subsection provides a description of the control logic block.
12.9.1 PWM Counter Registers
The PWM counter registers (PCNTH and PCNTL) display the 12-bit up/down or up-only counter. When
the high byte of the counter is read, the lower byte is latched. PCNTL will hold this latched value until it is
read. See Figure 12-33 and Figure 12-34.
Address: $0026
Bit 7
6
5
4
3
2
1
Bit 0
Read: 0
0
0
0
Bit 11
Bit 10
Bit 9
Bit 8
Write:
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 12-33. PWM Counter Register High (PCNTH)
Address: $0027
Bit 7
6
5
4
3
2
1
Bit 0
Read: Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Write:
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 12-34. PWM Counter Register Low (PCNTL)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Freescale Semiconductor
143