mc9s12vr48 Freescale Semiconductor, Inc, mc9s12vr48 Datasheet - Page 290

• Manufacturer Part Number: mc9s12vr48
• Description: S12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Pulse-Width Modulator (S12PWM8B8CV2)
The clock source of each PWM channel is determined by PCLKx bits in PWMCLK (see
“PWM Clock Select Register
and
9.3.2.8
PWMSCLA is the programmable scale value used in scaling clock A to generate clock SA. Clock SA is
generated by taking clock A, dividing it by the value in the PWMSCLA register and dividing that by two.
Any value written to this register will cause the scale counter to load the new scale value (PWMSCLA).
Read: Anytime
Write: Anytime (causes the scale counter to load the PWMSCLA value)
9.3.2.9
PWMSCLB is the programmable scale value used in scaling clock B to generate clock SB. Clock SB is
generated by taking clock B, dividing it by the value in the PWMSCLB register and dividing that by two.
Any value written to this register will cause the scale counter to load the new scale value (PWMSCLB).
Read: Anytime
Write: Anytime (causes the scale counter to load the PWMSCLB value).
290
Module Base + 0x0008
Module Base + 0x0009
Reset
Reset
Table
W
W
R
R
Clock SA = Clock A / (2 * PWMSCLA)
Clock SB = Clock B / (2 * PWMSCLB)
9-6.
Bit 7
Bit 7
PWM Scale A Register (PWMSCLA)
PWM Scale B Register (PWMSCLB)
0
0
7
7
When PWMSCLA = $00, PWMSCLA value is considered a full scale value
of 256. Clock A is thus divided by 512.
When PWMSCLB = $00, PWMSCLB value is considered a full scale value
of 256. Clock B is thus divided by 512.
0
0
6
6
6
6
Figure 9-10. PWM Scale A Register (PWMSCLA)
Figure 9-11. PWM Scale B Register (PWMSCLB)
(PWMCLK)) and PCLKABx bits in PWMCLKAB as shown in
MC9S12VR Family Reference Manual,
Preliminary - Subject to Change Without Notice
0
0
5
5
5
5
NOTE
NOTE
0
0
4
4
4
4
0
0
3
3
3
3
Rev. 2.2
0
0
2
2
2
2
Freescale Semiconductor
0
0
1
1
1
1
Section 9.3.2.3,
Table 9-5
Bit 0
Bit 0
0
0
0
0