Datasheet

Chapter 8 Pulse-Width Modulator (S12PWM8B8CV1)
MC9S12XDP512 Data Sheet, Rev. 2.21
376 Freescale Semiconductor
Read: Anytime
Write: Anytime (causes the scale counter to load the PWMSCLA value)
8.3.2.10 PWM Scale B Register (PWMSCLB)
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.
Clock SB = Clock B / (2 * PWMSCLB)
NOTE
When PWMSCLB = $00, PWMSCLB value is considered a full scale value
of 256. Clock B is thus divided by 512.
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).
8.3.2.11 Reserved Registers (PWMSCNTx)
The registers PWMSCNTA and PWMSCNTB are reserved for factory testing of the PWM module and are
not available in normal modes.
Read: Always read $00 in normal modes
Write: Unimplemented in normal modes
76543210
R
Bit 7 6 5 4 3 2 1 Bit 0
W
Reset 00000000
Figure 8-11. PWM Scale A Register (PWMSCLA)
76543210
R
Bit 7 6 5 4 3 2 1 Bit 0
W
Reset 00000000
Figure 8-12. PWM Scale B Register (PWMSCLB)
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 8-13. Reserved Registers (PWMSCNTx)