HD6473032F16 Datasheet, PDF (225/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 8 DMA Controller
In repeat mode, ETCRH functions as an 8-bit transfer counter and ETCRL holds the initial
transfer count. ETCRH is decremented by 1 each time one transfer is executed. When ETCRH
reaches H'00, the value in ETCRL is reloaded into ETCRH and the same operation is repeated.
The ETCRs are not initialized by a reset or in standby mode.
8.2.4 Data Transfer Control Registers (DTCR)
A data transfer control register (DTCR) is an 8-bit readable/writable register that controls the
operation of one DMAC channel.
Bit
Initial value
Read/Write
7
DTE
0
R/W
6
DTSZ
0
R/W
5
DTID
0
R/W
4
RPE
0
R/W
3
DTIE
0
R/W
2
DTS2
0
R/W
1
DTS1
0
R/W
0
DTS0
0
R/W
Data transfer enable
Enables or disables
data transfer
Data transfer select
These bits select the data
transfer activation source
Data transfer size
Selects byte or
word size
Data transfer interrupt enable
Enables or disables the CPU interrupt
at the end of the transfer
Data transfer
increment/decrement
Selects whether to
increment or decrement
the memory address
register
Repeat enable
Selects repeat
mode
The DTCRs are initialized to H'00 by a reset and in standby mode.
Bit 7—Data Transfer Enable (DTE): Enables or disables data transfer on a channel. When the
DTE bit is set to 1, the channel waits for a transfer to be requested, and executes the transfer when
activated as specified by bits DTS2 to DTS0. When DTE is 0, the channel is disabled and does not
accept transfer requests. DTE is set to 1 by reading the register when DTE is 0, then writing 1.
Bit 7: DTE
0
1
Description
Data transfer is disabled. In I/O mode or idle mode, DTE is cleared to 0 when
the specified number of transfers have been completed.
(Initial value)
Data transfer is enabled
Rev. 3.00 Mar 21, 2006 page 195 of 814
REJ09B0302-0300