HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 269

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

Block Transfer Mode
ETCRA
ETCRB
In block transfer mode, ETCRAL functions as an 8-bit block size counter and ETCRAH holds the
block size. ETCRAL is decremented each time a 1-byte or 1-word transfer is performed, and when
the count reaches H'00, ETCRAL is loaded with the value in ETCRAH. So by setting the block
size in ETCRAH and ETCRAL, it is possible to repeatedly transfer blocks consisting of any
desired number of bytes or words.
ETCRB functions in block transfer mode, as a 16-bit block transfer counter. ETCRB is
decremented by 1 each time a block is transferred, and transfer ends when the count reaches
H'0000.
Block Size Storage (ETCRAH)
Bit
Initial value :
R/W
Block Size Counter (ETCRAL)
Bit
Initial value :
R/W
Block Transfer Counter
Bit
Initial value :
R/W
:
:
:
:
:
: R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
15
*
R/W
R/W
15
7
*
*
14
*
13
*
R/W
R/W
14
6
*
*
12
*
11
Section 7 DMA Controller (Not Supported in the H8S/2321)
*
R/W
R/W
13
*
5
*
10
*
9
*
R/W
R/W
12
4
*
*
8
*
Rev.6.00 Sep. 27, 2007 Page 239 of 1268
7
*
R/W
R/W
11
3
*
*
6
*
5
*
R/W
R/W
10
2
*
*
4
*
REJ09B0220-0600
3
*
R/W
R/W
9
*
1
*
2
*
*: Undefined
*: Undefined
1
*
R/W
R/W
8
0
*
*
0
*