Datasheet

Chapter 11 Pulse Width Modulator with Fault Protection (PMF15B6C) Module
MC9S12E256 Data Sheet, Rev. 1.10
Freescale Semiconductor 355
11.3.2.28 PMF Counter Modulo B Register (PMFMODB)
Read anytime and write only if MTG is set.
The 15-bit unsigned value written to this register is the PWM period in PWM clock periods. Do not write
a modulus value of zero.
NOTE
The PWM counter modulo register is buffered. The value written does not
take effect until the LDOKB bit is set and the next PWM load cycle begins.
Reading PMFMODB reads the value in the buffer. It is not necessarily the
value the PWM generator B is currently using.
11.3.2.29 PMF Deadtime B Register (PMFDTMB)
Read anytime and write only if MTG is set. This register cannot be modified after the WP bit is set.
The 12-bit value written to this register is the number of PWM clock cycles in complementary channel
operation. A reset sets the PWM deadtime register to a default value of 0x0FFF, selecting a deadtime of
4096-PWM clock cycles minus one bus clock cycle.
NOTE
Deadtime is affected by changes to the prescaler value. The deadtime
duration is determined as follows: DT = P × PMFDTMB – 1, where DT is
deadtime, P is the prescaler value, PMFDTMB is the programmed value of
dead time. For example: if the prescaler is programmed for a divide-by-two
and the PMFDTMB is set to five, then P = 2 and the deadtime value is equal
to DT = 2 × 5 – 1 = 9 IPbus clock cycles. A special case exists when the
P = 1, then DT = PMFDTMB.
Address: $002C
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R0
PMFMODB
W
Reset 0 0 0 0 0 0 0 0 0 0000000
= Unimplemented or Reserved
Figure 11-34. PMF Counter Modulo B Register (PMFMODB)
Address: $002E
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R0 0 0 0
PMFDTMB
W
Reset 0 0 0 0 1 1 1 1 1 1111111
= Unimplemented or Reserved
Figure 11-35. PMF Deadtime B Register (PMFDTMB)