ECAP1
module
Interrupt
Controller
From EPWM
ECAP1INT
SyncIn
VBus32
SyncOut
ECAP2/
SyncOut
APWM2
module
SyncIn
ECAP2INT
SyncOut
SyncIn
module
APWMx
ECAPx/
ECAPxINT
ECAP1
GPIO
MUX
ECAP2
ECAPx
Enhanced Capture (eCAP) Module
15.3.2 Functional Description
The eCAP module represents one complete capture channel that can be instantiated multiple times
depending on the target device. In the context of this guide, one eCAP channel has the following
independent key resources:
•
Dedicated input capture pin
•
32-bit time base counter
•
4 × 32-bit time-stamp capture registers (CAP1-CAP4)
•
4-stage sequencer (Modulo4 counter) that is synchronized to external events, ECAP pin rising/falling
edges.
•
Independent edge polarity (rising/falling edge) selection for all 4 events
•
Input capture signal prescaling (from 2-62)
•
One-shot compare register (2 bits) to freeze captures after 1 to 4 time-stamp events
•
Control for continuous time-stamp captures using a 4-deep circular buffer (CAP1-CAP4) scheme
•
Interrupt capabilities on any of the 4 capture events
Multiple identical eCAP modules can be contained in a system as shown in
. The number of
modules is device-dependent and is based on target application needs. In this chapter, the letter x within a
signal or module name is used to indicate a generic eCAP instance on a device.
Figure 15-100. Multiple eCAP Modules
1608
Pulse-Width Modulation Subsystem (PWMSS)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated