mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 374

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Pulse-Width Modulator (S12PWM8B8CV1)
Read: Anytime
Write: Anytime
374
Module Base + 0x0003
PCKB[2:0]
PCKA[2:0]
s
Reset
Field
6–4
2–0
W
R
Prescaler Select for Clock B — Clock B is one of two clock sources which can be used for channels 2, 3, 6, or
7. These three bits determine the rate of clock B, as shown in
Prescaler Select for Clock A — Clock A is one 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
0
0
7
PCKB2–0 and PCKA2–0 register bits can be written anytime. If the clock
pre-scale is changed while a PWM signal is being generated, a truncated or
stretched pulse can occur during the transition.
= Unimplemented or Reserved
Figure 13-6. PWM Prescale Clock Select Register (PWMPRCLK)
PCKB2
PCKB2
PCKA2
0
6
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Table 13-4. PWMPRCLK Field Descriptions
S12XS Family Reference Manual, Rev. 1.10
Table 13-5. Clock B Prescaler Selects
Table 13-6. Clock A Prescaler Selects
PCKB1
PCKB1
0
PCKA1
5
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
PCKB0
NOTE
PCKB0
0
4
PCKA0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Description
0
0
3
Value of Clock B
Value of Clock A
Table
Table
Bus clock / 128
Bus clock / 128
Bus clock / 16
Bus clock / 32
Bus clock / 16
Bus clock / 32
Bus clock / 64
Bus clock / 64
Bus clock / 2
Bus clock / 4
Bus clock / 8
Bus clock / 2
Bus clock / 4
Bus clock / 8
Bus clock
Bus clock
13-5.
13-6.
PCKA2
0
2
PCKA1
Freescale Semiconductor
0
1
PCKA0
0
0