Registers
779
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
C28 Enhanced Pulse Width Modulator (ePWM) Module
7.4.2 Counter-Compare Submodule Registers
through
and
through
illustrate the counter-compare
submodule control and status registers.
Figure 7-87. Counter-Compare Control Register (CMPCTL)
15
14
13
12
11
10
9
8
Reserved
LOADBSYNC
LOADASYNC
SHDWBFULL
SHDWAFULL
R-0
7
6
5
4
3
2
1
0
Reserved
SHDWBMODE
Reserved
SHDWAMODE
LOADBMODE
LOADAMODE
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 7-37. Counter-Compare Control Register (CMPCTL) Field Descriptions
Bit
Field
Value
Description
15-14
Reserved
0
Reserved
13-12
LOADBSYNC
Shadow to Active CMPB Register Load on SYNC event
00
Shadow to Active Load of CMPB:CMPBHR occurs according to LOADBMODE (bits 1,0) (same as
legacy)
01
Shadow to Active Load of CMPB:CMPBHR occurs both according to LOADBMODE bits and when
SYNC occurs
10
Shadow to Active Load of CMPB:CMPBHR occurs only when a SYNC is received.
11
Reserved
Note:
This bit is valid only if CMPCTL[SHDWBMODE] = 0.
11-10
LOADASYNC
Shadow to Active CMPA Register Load on SYNC event
00
Shadow to Active Load of CMPA:CMPAHR occurs according to LOADAMODE (bits 1,0) (same as
legacy)
01
Shadow to Active Load of CMPA:CMPAHR occurs both according to LOADAMODE bits and when
SYNC occurs.
10
Shadow to Active Load of CMPA:CMPAHR occurs only when a SYNC is received.
11
Reserved
Note:
This bit is valid only if CMPCTL[SHDWAMODE] = 0.
9
SHDWBFULL
Counter-compare B (CMPB) Shadow Register Full Status Flag. This bit self clears once a load-
strobe occurs.
0
CMPB shadow FIFO not full yet
1
Indicates the CMPB shadow FIFO is full; a CPU write will overwrite current shadow value.
8
SHDWAFULL
Counter-compare A (CMPA) Shadow Register Full Status Flag The flag bit is set when a 32-bit
write to CMPA:CMPAHR register or a 16-bit write to CMPA register is made. A 16-bit write to
CMPAHR register will not affect the flag.
This bit self clears once a load-strobe occurs.
0
CMPA shadow FIFO not full yet
1
Indicates the CMPA shadow FIFO is full, a CPU write will overwrite the current shadow value.
7
Reserved
0
Reserved
6
SHDWBMODE
Counter-compare B (CMPB) Register Operating Mode
0
Shadow mode. Operates as a double buffer. All writes via the CPU access the shadow register.
1
Immediate mode. Only the active compare B register is used. All writes and reads directly access
the active register for immediate compare action
5
Reserved
Reserved
4
SHDWAMODE
Counter-compare A (CMPA) Register Operating Mode
0
Shadow mode. Operates as a double buffer. All writes via the CPU access the shadow register.
1
Immediate mode. Only the active compare register is used. All writes and reads directly access the
active register for immediate compare action