37.5.2.4 PWM Generation
illustrates how PWM generation is accomplished in each submodule. In
each case, two comparators and associated VALx registers are utilized for each PWM
output signal. One comparator and VALx register are used to control the turn-on edge,
while a second comparator and VALx register control the turn-off edge.
Q
PWM off
Q
VAL0
VAL1
VAL2
VAL3
VAL4
VAL5
Output Triggers
Q
PWM on
Half Comp
FORCE_OUT
Force Init
16 bit counter
FRCEN
PWMX
PWM23
PWM45
Mod Comp
PWM off
PWM on
PWM45_INIT
PWM on
PWM23_INIT
PWMX_INIT
PWM off
S
S
D
R
S
D
R
D
R
16 bit
comparator
(inverted
Local Sync)
to Force Out
logic
16 bit
comparator
16 bit
comparator
16 bit
comparator
16 bit
comparator
16 bit
comparator
16 bit
comparator
Figure 37-237. PWM Generation Hardware
The generation of the Local Sync signal is performed exactly the same way as the other
PWM signals in the submodule. While comparator 0 causes a falling edge of the Local
Sync signal, comparator 1 generates a rising edge. Comparator 1 is also hardwired to the
reload logic to generate the full cycle reload indicator.
If VAL1 is controlling the modulus of the counter and VAL0 is half of the VAL1 register
minus the INIT value, then the half cycle reload pulse will occur exactly half way
through the timer count period and the Local Sync will have a 50% duty cycle. On the
other hand, if the VAL1 and VAL0 registers are not required for register reloading or
Chapter 37 Pulse Width Modulator A (PWMA/eFlexPWM)
KV4x Reference Manual, Rev. 2, 02/2015
Freescale Semiconductor, Inc.
Preliminary
839
Содержание freescale KV4 Series
Страница 2: ...KV4x Reference Manual Rev 2 02 2015 2 Preliminary Freescale Semiconductor Inc...
Страница 60: ...KV4x Reference Manual Rev 2 02 2015 60 Preliminary Freescale Semiconductor Inc...
Страница 82: ...JTAG Controller Configuration KV4x Reference Manual Rev 2 02 2015 82 Preliminary Freescale Semiconductor Inc...
Страница 88: ...System Register file KV4x Reference Manual Rev 2 02 2015 88 Preliminary Freescale Semiconductor Inc...
Страница 128: ...Debug Security KV4x Reference Manual Rev 2 02 2015 128 Preliminary Freescale Semiconductor Inc...
Страница 138: ...Boot KV4x Reference Manual Rev 2 02 2015 138 Preliminary Freescale Semiconductor Inc...
Страница 150: ...Pinout diagrams KV4x Reference Manual Rev 2 02 2015 150 Preliminary Freescale Semiconductor Inc...
Страница 170: ...Functional description KV4x Reference Manual Rev 2 02 2015 170 Preliminary Freescale Semiconductor Inc...
Страница 212: ...Functional description KV4x Reference Manual Rev 2 02 2015 212 Preliminary Freescale Semiconductor Inc...
Страница 284: ...Functional description KV4x Reference Manual Rev 2 02 2015 284 Preliminary Freescale Semiconductor Inc...
Страница 294: ...Functional description KV4x Reference Manual Rev 2 02 2015 294 Preliminary Freescale Semiconductor Inc...
Страница 330: ...Functional description KV4x Reference Manual Rev 2 02 2015 330 Preliminary Freescale Semiconductor Inc...
Страница 450: ...Initialization application information KV4x Reference Manual Rev 2 02 2015 450 Preliminary Freescale Semiconductor Inc...
Страница 512: ...Interrupts and DMA Requests KV4x Reference Manual Rev 2 02 2015 512 Preliminary Freescale Semiconductor Inc...
Страница 520: ...Memory Map and Register Descriptions KV4x Reference Manual Rev 2 02 2015 520 Preliminary Freescale Semiconductor Inc...
Страница 580: ...Initialization Application information KV4x Reference Manual Rev 2 02 2015 580 Preliminary Freescale Semiconductor Inc...
Страница 660: ...Functional description KV4x Reference Manual Rev 2 02 2015 660 Preliminary Freescale Semiconductor Inc...
Страница 1038: ...Example configuration for chained timers KV4x Reference Manual Rev 2 02 2015 1038 Preliminary Freescale Semiconductor Inc...
Страница 1074: ...Functional description KV4x Reference Manual Rev 2 02 2015 1074 Preliminary Freescale Semiconductor Inc...
Страница 1168: ...Initialization application information KV4x Reference Manual Rev 2 02 2015 1168 Preliminary Freescale Semiconductor Inc...
Страница 1264: ...Initialization application information KV4x Reference Manual Rev 2 02 2015 1264 Preliminary Freescale Semiconductor Inc...
Страница 1336: ...Functional description KV4x Reference Manual Rev 2 02 2015 1336 Preliminary Freescale Semiconductor Inc...
Страница 1358: ...KV4x Reference Manual Rev 2 02 2015 1358 Preliminary Freescale Semiconductor Inc...