MC9S12Q FREESCALE [Freescale Semiconductor, Inc], MC9S12Q Datasheet - Page 355

• Manufacturer Part Number: MC9S12Q
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

12.3.2.4
This register selects the prescale clock source for clocks A and B independently.
Read: anytime
Write: anytime
Freescale Semiconductor
Module Base + 0x0003
PCKB[2:0]
PCKA[2:0]
Reset
Field
6–5
2–0
W
R
Prescaler Select for Clock B — Clock B is 1 of two clock sources which can be used for channels 2 or 3. These
three bits determine the rate of clock B, as shown in
Prescaler Select for Clock A — Clock A is 1 of two clock sources which can be used for channels 0, 1, 4, or 5.
These three bits determine the rate of clock A, as shown in
PWM Prescale Clock Select Register (PWMPRCLK)
0
0
7
PCKB2–PCKB0 and PCKA2–PCKA0 register bits can be written anytime.
If the clock prescale is changed while a PWM signal is being generated, a
truncated or stretched pulse can occur during the transition.
Figure 12-6. PWM Prescaler Clock Select Register (PWMPRCLK)
= Unimplemented or Reserved
PCKB2
PCKB2
0
0
0
0
1
1
1
1
0
6
Table 12-4. PWMPRCLK Field Descriptions
Table 12-5. Clock B Prescaler Selects
PCKB1
PCKB1
0
5
0
0
1
1
0
0
1
1
MC9S12Q128
PCKB0
Rev 1.09
NOTE
PCKB0
0
4
0
1
0
1
0
1
0
1
Chapter 12 Pulse-Width Modulator (PWM8B4C) Block Description
Description
Table
12-5.
Table
0
0
3
Value of Clock B
Bus Clock / 128
12-6.
Bus Clock / 16
Bus Clock / 32
Bus Clock / 64
Bus Clock / 2
Bus Clock / 4
Bus Clock / 8
Bus Clock
PCKA2
0
2
PCKA1
0
1
PCKA0
0
0
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