HD6413007F20 Datasheet, PDF (229/798 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

7. DMA Controller
7.3.3 Execute Transfer Count Registers (ETCR)
An execute transfer count register (ETCR) is a 16-bit readable/writable register that specifies the
number of transfers to be executed. The functions of these registers differ between normal mode
and block transfer mode.
Normal mode
• ETCRA
Bit
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Initial value
Undetermined
Read/Write 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
Transfer counter
• ETCRB: Is not used in normal mode.
In normal mode ETCRA functions as a 16-bit transfer counter. The count is decremented by 1
each time one transfer is executed. The transfer ends when the count reaches H'0000. ETCRB
is not used.
Block transfer mode
• ETCRA
Bit
7
6
5
4
3
2
1
0
Initial value
Undetermined
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
ETCRAH
Block size counter
Bit
7
6
5
4
3
2
1
0
Initial value
Undetermined
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
ETCRAL
Initial block size
Rev.5.00 Sep. 12, 2007 Page 199 of 764
REJ09B0396-0500