ISD94100 Series Technical Reference Manual
Sep 9, 2019
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CMPDAT DATA0
CMPU
CMPDAT DATA1
PERIOD DATA1
PERIOD DATA2
PERIOD DATA0
CNT
CNT wraparound
0xFFFF
Write
Load
Note:
CMPDAT
PERIOD
PERIOD DATA0
PERIOD DATA1
CMPDAT DATA1
PBUF
PERIOD DATA0
PERIOD DATA1
CMPBUF
CMPDAT DATA1
PERIOD DATA2
PERIOD DATA2
point 1
point 2
point 3
Figure 6.8-14 Immediately Loading in Up-Count Mode
6.8.5.10 Window Loading Mode
When the WINLDENn (PWM_CTL0[13:8]) bit is set to 1, PWM operates at window loading mode.
In Window loading mode, CLKPSC(PWM_CLKPSCn_m[11:0]), PERIOD(PWM_PERIODn[15:0])
and CMP(PWM_CMPDATn[15:0]) will all load to their active CPSCBUF, PBUF and CMPBUF
registers while each period is completed, but all loading are valid only when load window is opened.
Every channel n’s load window is opened by setting the corresponding LOADn (PWM_LOAD[5:0])
to 1, and hardware will close the window at the end of PWM period. Figure 6.8-15 shows an example
and its steps sequence is described below.
1. Software writes CMPDAT DATA1 at point 1, and the load window is not opened at this period
so CMPDAT will not load to CMPBUF.
2. Software writes LOAD to open the load window at point2.
3. Software writes PERIOD DATA1 at point 3.
4. At point 4, load window has been opened, hardware loads CLKPSC DATA1, PERIOD DATA1
and CMPDAT DATA1 to their buffer and closes the load window at the end of PWM period.
5. Software writes PERIOD DATA2 at point 5.
6. Hardware loads CLKPSC DATA2, PERIOD DATA2 to PBUF at the end of PWM period at point
6.
7. Software writes PERIOD DATA3 at point 7.
8. Software writes LOAD to open the load window at point8.
9. Hardware loads CLKPSC DATA3 and PERIOD DATA3 to their buffer and closes the load
window at the end of PWM period at point 9.