Texas Instruments TMS570LC4357 - Page 1930

Polarity
select
Polarity
select
Polarity
select
SYNC
TSCTR
(counter-32 bit)
RST
CAP1
(APRD active)
LD
CAP2
(ACMP active)
LD
CAP3
(APRD shadow)
LD
CAP4
(ACMP shadow)
LD
Continuous /
Oneshot
Capture Control
LD1
LD2
LD3
LD4
32
32
PRD [0-31]
CMP [0-31]
CTR [0-31]
ECAPx
Interrupt
Trigger
and
Flag
control
to VIM
CTR=CMP
32
32
32
32
32
ACMP
shadow
Event
Prescale
CTRPHS
(phase register-32 bit)
SYNCOut
SYNCIn
Event
qualifier
Polarity
select
CTR=PRD
CTR_OVF
4
PWM
compare
logic
CTR [0-31]
PRD [0-31]
CMP [0-31]
CTR=CMP
CTR=PRD
CTR_OVF
OVF
APWM mode
Delta-mode
4
Captureevents
CEVT[1:4]
APRD
shadow
32
32
MODE SELECT
ECCTL2 [ SYNCI_EN, SYNCOSEL, SWSYNC]
ECCTL2[CAP/APWM]
EdgePolaritySelect
ECCTL1[CAPxPOL]
ECCTL1[EVTPS]
ECCTL1 [ CAPLDEN, CTRRSTx]
ECCTL2 [ RE-ARM, CONT/ONESHT, STOP_WRAP]
Registers: ECEINT, ECFLG, ECCLR, ECFRC
Basic Operation www.ti.com
1930
SPNU563A–March 2018
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Enhanced Capture (eCAP) Module
33.2.2 Capture Mode Description
Figure 33-2 shows the various components that implement the capture function.
Figure 33-2. Capture Function Diagram
33.2.2.1 Event Prescaler
• An input capture signal (pulse train) can be prescaled by N = 2-62 (in multiples of 2) or can bypass the
prescaler.
This is useful when very high frequency signals are used as inputs. Figure 33-3 shows a functional
diagram and Figure 33-4 shows the operation of the prescale function.