MC9S12E256 Datasheet, PDF (346/602 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 11 Pulse Width Modulator with Fault Protection (PMF15B6CV2)
Table 11-33. PMFFQCB Field Descriptions (continued)
Field
Description
2–1
PRSCB
Prescaler B — This buffered field selects the PWM clock frequency illustrated in Table 11-35.
Note: Reading the PRSCB field reads the buffered value and not necessarily the value currently in effect. The
PRSCB field takes effect at the beginning of the next PWM cycle and only when the load okay bit, LDOKB,
is set.
0
PWMRFB
PWM Reload Flag B — This flag is set at the beginning of every reload cycle regardless of the state of the
LDOKB bit. Clear PWMRFB by reading PMFFQCB with PWMRFB set and then writing a logic one to the
PWMRFB bit. If another reload occurs before the clearing sequence is complete, writing logic one to PWMRFB
has no effect.
0 No new reload cycle since last PWMRFB clearing
1 New reload cycle since last PWMRFB clearing
Note: Clearing PWMRFB satisfies pending PWMRFB CPU interrupt requests.
LDFQB
0000
0001
0010
0011
0100
0101
0110
0111
Table 11-34. PWM Reload Frequency B
PWM Reload Frequency
Every PWM opportunity
Every 2 PWM opportunities
Every 3 PWM opportunities
Every 4 PWM opportunities
Every 5 PWM opportunities
Every 6 PWM opportunities
Every 7 PWM opportunities
Every 8 PWM opportunities
LDFQ[3:0]
1000
1001
1010
1011
1100
1101
1110
1111
PWM Reload Frequency
Every 9 PWM opportunities
Every 10 PWM opportunities
Every 11 PWM opportunities
Every 12 PWM opportunities
Every 13 PWM opportunities
Every 14 PWM opportunities
Every 15 PWM opportunities
Every 16 PWM opportunities
Table 11-35. PWM Prescaler B
PRSCB
00
01
10
11
PWM Clock Frequency
f_bus
f_bus/2
f_bus/4
f_bus/8
MC9S12E256 Data Sheet, Rev. 1.08
346
Freescale Semiconductor