Functional Description
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Note that PaRAM updates only pertain to the information that is needed to properly submit the next
transfer request to the EDMA3TC. Updates that occur while data is moved within a transfer request are
tracked within the transfer controller, and is detailed in Section 11.3.12. For A-synchronized transfers, the
EDMA3CC always submits a TRP for ACNT bytes (BCNT = 1 and CCNT = 1). For AB-synchronized
transfers, the EDMA3CC always submits a TRP for ACNT bytes of BCNT arrays (CCNT = 1). The
EDMA3TC is responsible for updating source and destination addresses within the array based on ACNT
and FWID (in OPT). For AB-synchronized transfers, the EDMA3TC is also responsible to update source
and destination addresses between arrays based on SRCBIDX and DSTBIDX.
Table 11-9 shows the details of parameter updates that occur within EDMA3CC for A-synchronized and
AB-synchronized transfers.
Table 11-9. Parameter Updates in EDMA3CC (for Non-Null, Non-Dummy PaRAM Set)
A-Synchronized Transfer AB-Synchronized Transfer
B-Update C-Update Link Update B-Update C-Update Link Update
BCNT == 1 && BCNT == 1 &&
Condition: BCNT > 1 CCNT > 1 CCNT == 1 N/A CCNT > 1 CCNT == 1
SRC += SRCBIDX += SRCCIDX = Link.SRC in EDMA3TC += SRCCIDX = Link.SRC
DST += DSTBIDX += DSTCIDX = Link.DST in EDMA3TC += DSTCIDX = Link.DST
ACNT None None = Link.ACNT None None = Link.ACNT
BCNT –= 1 = BCNTRLD = Link.BCNT in EDMA3TC N/A = Link.BCNT
CCNT None –= 1 = Link.CCNT in EDMA3TC –=1 = Link.CCNT
SRCBIDX None None = Link.SRCBIDX in EDMA3TC None = Link.SRCBIDX
DSTBIDX None None = Link.DSTBIDX None None = Link.DSTBIDX
SRCCIDX None None = Link.SRCBIDX in EDMA3TC None = Link.SRCBIDX
DSTCIDX None None = Link.DSTBIDX None None = Link.DSTBIDX
LINK None None = Link.LINK None None = Link.LINK
BCNTRLD None None = Link.BCNTRLD None None = Link.BCNTRLD
OPT
(1)
None None = LINK.OPT None None = LINK.OPT
(1)
In all cases, no updates occur if OPT.STATIC == 1 for the current PaRAM set.
NOTE: The EDMA3CC includes no special hardware to detect when an indexed address update
calculation overflows/underflows. The address update will wrap across boundaries as
programmed by the user. You should ensure that no transfer is allowed to cross internal port
boundaries between peripherals. A single TR must target a single source/destination slave
endpoint.
890
Enhanced Direct Memory Access (EDMA) SPRUH73H–October 2011–Revised April 2013
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