Enhanced PWM (ePWM) Module
Table 15-10. Submodule Configuration Parameters (continued)
Submodule
Configuration Parameter or Option
Trip-zone (TZ)
• Configure the ePWM module to react to one, all, or none of the trip-zone pins.
• Specify the tripping action taken when a fault occurs:
–
Force EPWMxA and/or EPWMxB high
–
Force EPWMxA and/or EPWMxB low
–
Force EPWMxA and/or EPWMxB to a high-impedance state
–
Configure EPWMxA and/or EPWMxB to ignore any trip condition.
• Configure how often the ePWM will react to each trip-zone pin:
–
One-shot
–
Cycle-by-cycle
• Enable the trip-zone to initiate an interrupt.
• Bypass the trip-zone module entirely.
Event-trigger (ET)
• Enable the ePWM events that will trigger an interrupt.
• Specify the rate at which events cause triggers (every occurrence or every second or third
occurrence)
• Poll, set, or clear event flags
High-Resolution PWM
• Enable extended time resolution capabilities
(HRPWM)
• Configure finer time granularity control or edge positioning
Code examples are provided in the remainder of this chapter that show how to implement various ePWM
module configurations. These examples use the constant definitions shown in
Example 15-1. Constant Definitions Used in the Code Examples
// TBCTL (Time-Base Control)
// = = = = = = = = = = = = = = = = = = = = = = = = = =
// TBCNT MODE bits
#define
TB_COUNT_UP
0x0
#define
TB_COUNT_DOWN
0x1
#define
TB_COUNT_UPDOWN
0x2
#define
TB_FREEZE
0x3
// PHSEN bit
#define
TB_DISABLE
0x0
#define
TB_ENABLE
0x1
// PRDLD bit
#define
TB_SHADOW
0x0
#define
TB_IMMEDIATE
0x1
// SYNCOSEL bits
#define
TB_SYNC_IN
0x0
#define
TB_CTR_ZERO
0x1
#define
TB_CTR_CMPB
0x2
#define
TB_SYNC_DISABLE
0x3
// HSPCLKDIV and CLKDIV bits
#define
TB_DIV1
0x0
#define
TB_DIV2
0x1
#define
TB_DIV4
0x2
// PHSDIR bit
#define
TB_DOWN
0x0
#define
TB_UP
0x1
// CMPCTL (Compare Control)
// = = = = = = = = = = = = = = = = = = = = = = = = = =
// LOADAMODE and LOADBMODE bits
#define
CC_CTR_ZERO
0x0
#define
CC_CTR_PRD
0x1
#define
CC_CTR_ZERO_PRD
0x2
#define
CC_LD_DISABLE
0x3
1499
SPRUH73H – October 2011 – Revised April 2013
Pulse-Width Modulation Subsystem (PWMSS)
Copyright © 2011–2013, Texas Instruments Incorporated