TC1796
System Units (Vol. 1 of 2)
Direct Memory Access Controller
User’s Manual
12-14
V2.0, 2007-07
DMA, V2.0
Figure 12-8 Hardware-controlled Single Mode Operation
Hardware-controlled Continuous Mode
In hardware-controlled Continuous Mode (CHCRmn.CHMODE = 1), the hardware
transaction request enable bit HTREmn is not cleared at the end of a DMA transaction.
A new transaction of DMA channel mn with the parameters actually stored in the channel
register set of DMA channel mn is started each time when CHSRmn.TCOUNT reaches
000
H
. No software re-enable for a hardware request at CHmn_REQ is required.
MCT05687
tc = initial transfer count
tc = initial transfer count
CHCRmn.RROAT = 1
CHCRmn.RROAT = 0
TR0
TR1
TRn
tc-1
TR0
TR1
0
tc
tc-1
0
1
tc
TR0
tc-1
tc
TR1
TRn-1
TRn
0
0
2
1
tc
TR0
TRSR.HTREmn
CHmn_REQ
INT
(triggered at the end
of a transaction with
IRDV = 0)
CHSRmn.TCOUNT
DMA Transfer mn
TRSR.CHmn
TRSR.HTREmn
CHmn_REQ
TRSR.CHmn
DMA Transfer mn
CHSRmn.TCOUNT
INT
(triggered at the end
of a transaction with
IRDV = 0)