Freescale Semiconductor MC68HC908MR32 - Manual (Page 150)

Pulse-Width Modulator for Motor Control (PWMMC)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
150 Freescale Semiconductor
12.9.6 Dead-Time Write-Once Register
The dead-time write-once register (DEADTM) holds an 8-bit value which specifies the number of CPU
clock cycles to use for the dead-time when complementary PWM mode is selected. After this register is
written for the first time, it cannot be rewritten unless a reset occurs. Dead-time is not affected by changes
to the prescaler value.
12.9.7 PWM Disable Mapping Write-Once Register
The PWM disable mapping write-once register (DISMAP) holds an 8-bit value which determines which
PWM pins will be disabled if an external fault or software disable occurs. For a further description of
disable mapping, see
12.6 Fault Protection . After this register is written for the first time, it cannot be
rewritten unless a reset occurs.
12.9.8 Fault Control Register
The fault control register (FCR) controls the fault-protection circuitry.
FINT4 — Fault 4 Interrupt Enable Bit
This read/write bit allows the CPU interrupt caused by faults on fault pin 4 to be enabled. The fault
protection circuitry is independent of this bit and will always be active. If a fault is detected, the PWM
pins will still be disabled according to the disable mapping register.
1 = Fault pin 4 will cause CPU interrupts.
0 = Fault pin 4 will not cause CPU interrupts.
Address: $0036
Bit 7 6 5 4 3 2 1 Bit 0
Read:
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Write:
Reset: 1 1 1 1 1 1 1 1
Figure 12-41. Dead-Time Write-Once Register (DEADTM)
Address: $0037
Bit 7 6 5 4 3 2 1 Bit 0
Read:
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Write:
Reset: 1 1 1 1 1 1 1 1
Figure 12-42. PWM Disable Mapping Write-Once Register (DISMAP)
Address: $0022
Bit 7 6 5 4 3 2 1 Bit 0
Read:
FINT4 FMODE4 FINT3 FMODE3 FINT2 FMODE2 FINT1 FMODE1
Write:
Reset: 0 0 0 0 0 0 0 0
Figure 12-43. Fault Control Register (FCR)