17-54
MPC561/MPC563 Reference Manual
MOTOROLA
MIOS14 Pulse Width Modulation Submodule (MPWMSM)
17.10.3.7 MPWMSM Status and Control Register (SCR)
One register is used to initialize the MPWMSM and monitor its operation. Control bits are
included to allow the software to enable the PWM generator, establish the output signal
polarity, select the counter clock rate and set the glitch-free mode. A status bit is included
to allow the software to read the state of the output signal.
17.10.3.8 MPWMSM Interrupt
A valid MPWMSM interrupt is recognized when a pulse occurs on the flag line to set the
flag bit and the interrupt enable bit is set for the corresponding level in the MIRSM (Refer
interrupts). A set flag pulse is generated at the start of every period.
The flag bit is a status bit which indicates, when set, that the output period has started and
that registers MPWMPERR and MPWMPULR1 are available for updates when in
double-buffered mode. The level of the resulting interrupt is determined in the MIRSM.
17.10.3.9 MPWMSM Port Functions
The MPWMSM has one dedicated I/O external signal.
The output flip-flop is the basic output of the MPWMSM. Except when the pulse width is
at 100% or 0%, the output flip-flop is reset at the beginning of each period and is set at the
beginning of the designated pulse width until the end of the period. As a software option,
the polarity of the signal presented to the output signal may be the state of the output
flip-flop or the inverse of the output flip-flop.
38.4
s/1536 0.397 0.795 1.589 3.179 6.358 12.71 25.43 50.86 101.7 203.5 406.9 813.8 1627 3255 6510
13K
44.8
s/1792 0.34 0.681 1.362 2.724 5.449 10.89 21.80 43.59 87.19 174.4 348.8 697.5 1395 2790 5580 11.1K
51.2
s/2048 0.298 0.596 1.192 2.384 4.768 9.536 19.07 38.14 76.29 152.5 305.1 610.3 1220 2441 4882
9765
57.6
s/2304 0.264 0.529 1.059 2.119 4.238 8.477 16.95 33.90 67.81 135.6 271.2 542.5 1085 2170 4340
8680
64
s/2560 0.238 0.476 0.953 1.907 3.814 7.629 15.24 30.51 61.03 122 244.1 488.2 976.5 1953 3906
7812
70.4
s/2816 0.216 0.433 0.867 1.734 3.468 6.936 13.87 27.74 55.48 110.9 221.9 443.9 887.8 1775 3551
7102
76.8
s/3072 0.198 0.397 0.795 1.589 3.179 6.358 12.71 25.43 50.86 101.7 203.5 406.9 813.8 1627 3255
6510
83.2
s/3328 0.183 0.366 0.733 1.467 2.934 5.869 11.74 23.47 46.95 93.9 187.8 375.6 751.2 1502 3004
6009
89.6
s/3584 0.170 0.340 0.681 1.362 2.724 5.449 10.89 21.80 43.59 87.19 174.4 348.8 697.5 1395 2790
5580
96
s/3840 0.159 0.318 0.636 1.271 2.543 5.086 10.17 20.34 40.69 81.38 162.8 325.5 651
1302
2604
5208
Table 17-24. PWM Pulse/Frequency Ranges (in Hz) Using /1 or /256 Option (40 MHz) (continued)
Minimum
Pulse Width
Bits of Resolution
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1