HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 303

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

7.5.7
In block transfer mode, transfer is performed with channels A and B used in combination. Block
transfer mode can be specified by setting the FAE bit in DMABCR and the BLKE bit in
DMACRA to 1.
In block transfer mode, a transfer of the specified block size is carried out in response to a single
transfer request, and this is executed the specified number of times. The transfer source is
specified by MARA, and the transfer destination by MARB. Either the transfer source or the
transfer destination can be selected as a block area (an area composed of a number of bytes or
words).
Table 7.11 summarizes register functions in block transfer mode.
Table 7.11 Register Functions in Block Transfer Mode
Register
23
23
Legend:
MARA: Memory address register A
MARB: Memory address register B
ETCRA: Execute transfer count register A
ETCRB: Execute transfer count register B
15
Block Transfer Mode
MARA
MARB
ETCRB
7
7
ETCRAH
ETCRAL
0
0
0
0
0
Function
Source address
register
Destination
address register
Holds block
size
Block size
counter
Block transfer
counter
Section 7 DMA Controller (Not Supported in the H8S/2321)
Initial Setting
Start address of
transfer source
Start address of
transfer destination
Block size
Block size
Number of block
transfers
Rev.6.00 Sep. 27, 2007 Page 273 of 1268
Operation
Incremented/decremented
every transfer, or fixed
Incremented/decremented
every transfer, or fixed
Fixed
Decremented every
transfer; ETCRH value
copied when count reaches
H'00
Decremented every block
transfer; transfer ends
when count reaches
H'0000
REJ09B0220-0600