HD64F3028F25 Datasheet, PDF (234/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Block Transfer Mode
• ETCRA
Bit
7
6
5
4
3
2
1
0
Initial value
Read/Write
Bit
Undetermined
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
ETCRAH
Block size counter
7
6
5
4
3
2
1
0
Initial value
Read/Write
Undetermined
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
ETCRAL
Initial block size
• ETCRB
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
Block transfer counter
In block transfer mode, ETCRAH functions as an 8-bit block size counter. ETCRAL holds the
initial block size. ETCRAH is decremented by 1 each time one byte or word is transferred. When
the count reaches H'00, ETCRAH is reloaded from ETCRAL. Blocks consisting of an arbitrary
number of bytes or words can be transferred repeatedly by setting the same initial block size value
in ETCRAH and ETCRAL.
In block transfer mode ETCRB functions as a 16-bit block transfer counter. ETCRB is
decremented by 1 each time one block is transferred. The transfer ends when the count reaches
H'0000.
The ETCRs are not initialized by a reset or in standby mode.
Rev. 2.00, 09/03, page 202 of 890