Registers
733
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
C28 Enhanced Pulse Width Modulator (ePWM) Module
7.4
Registers
This chapter includes the register layouts and bit description for the submodules.
7.4.1 Time-Base Submodule Registers
through
and
through
provide the time-base register
definitions.
Figure 7-75. Time-Base Period and Mirror 2 Register (TBPRD / TBPRDM2)
15
0
TBPRD
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 7-25. Time-Base Period and Mirror 2 Register (TBPRD / TBPRDM2) Field Descriptions
Bit
Field
Value
Description
15-0
TBPRD
0000-FFFFh
These bits determine the period of the time-base counter. This sets the PWM frequency.
Shadowing of this register is enabled and disabled by the TBCTL[PRDLD] bit. By default
this register is shadowed.
• If TBCTL[PRDLD] = 0, then the shadow is enabled and any write or read will
automatically go to the shadow register. In this case, the active register will be loaded
from the shadow register when the time-base counter equals zero.
• If TBCTL[PRDLD] = 1, then the shadow is disabled and any write or read will go
directly to the active register, that is the register actively controlling the hardware.
• The active and shadow registers share the same memory map address.
Figure 7-76. Time-Base Period High-Resolution and Mirror 2 Register (TBPRDHR / TBPRDHRM2)
15
8
TBPRDHR
R/W-0
7
0
Reserved
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 7-26. Time-Base Period High-Resolution and Mirror 2 Register (TBPRDHR / TBPRDHRM2)
Field Descriptions
Bit
Field
Value
Description
15-8
TBPRDHR
00-FFh
Period High Resolution Bits
These 8-bits contain the high-resolution portion of the period value.
The TBPRDHR register is not affected by the TBCTL[PRDLD] bit. Reads from this register always
reflect the shadow register. Likewise writes are also to the shadow register. The TBPRDHR register
is only used when the high resolution period feature is enabled.
This register is only available with ePWM modules which support high-resolution period control.
7-0
Reserved
0
Reserved
Figure 7-77. Time-Base Period Mirror Register (TBPRDM)
15
0
TBPRD
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset