ISD94100 Series Technical Reference Manual
Sep 9, 2019
Page
414
of 928
Rev1.09
IS
D
9
410
0
S
ER
IE
S
T
E
C
HN
ICA
L
RE
F
E
RE
NCE
M
AN
U
AL
CMPDAT DATA0
CMPU
CMPDAT DATA1
PERIOD DATA0
PERIOD DATA1
PERIOD DATA2
CNT
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 point 4
point 5
point 6
Figure 6.8-13 Period Loading in Up-Count Mode
6.8.5.9
Immediately Loading Mode
If the IMMLDENn (PWM_CTL0[21:16]) bit is set to 1, PWM operates at immediately loading mode.
In immediately loading mode, when user update CLKPSC(PWM_CLKPSCn_m[11:0]),
PERIOD(PWM_PERIODn[15:0]) or CMP(PWM_CMPDATn[15:0]), PERIOD or CMPDAT will be
load to active CPSCBUF (PWM_CPSCBUFn_m[15:0]), PBUF (PWM_PBUFn[15:0]) or CMPBUF
(PWM_CMPBUFn[15:0]) after current counter count is completed. If the updated PERIOD value is
less than current counter value, counter will count to 0xFFFF, when counter count to 0xFFFF and
prescale count to zero, the flag CNTMAXF(PWM0_STATUS[5:0]) will raise, and then counter will
count wraparound. Immediately loading mode has the highest priority. If IMMLDENn has been set,
other loading mode for channel n will become invalid. Figure 6.8-14 shows an example and its steps
sequence is described below.
1. Software writes CMPDAT DATA1 and hardware immediately loading CMPDAT DATA1 to
CMPBUF at point 1.
2. Software writes PERIOD DATA1 which is greater than current counter value at point 2; counter
will continue counting until equal to PERIOD DATA1 to finish a period loading.
3. Software writes PERIOD DATA2 which is less than the current counter value at point 3;
counter will continue counting to its maximum value 0xFFFF and count wraparound from 0 to
PERIOD DATA2 to finish this period loading.
