HD64F3028F25 Datasheet, PDF (56/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

2.5 Data Formats
The H8/300H CPU can process 1-bit, 4-bit (BCD), 8-bit (byte), 16-bit (word), and 32-bit
(longword) data. Bit-manipulation instructions operate on 1-bit data by accessing bit n (n = 0, 1,
2, …, 7) of byte operand data. The DAA and DAS decimal-adjust instructions treat byte data as
two digits of 4-bit BCD data.
2.5.1 General Register Data Formats
Figures 2.6 and 2.7 show the data formats in general registers.
Data Type
1-bit data
General
Register
RnH
1-bit data
RnL
4-bit BCD data
RnH
4-bit BCD data
RnL
Byte data
RnH
Byte data
RnL
Legend
RnH: General register RH
RnL: General register RL
Data Format
7
0
76543210
Don’t care
Don’t care
7
0
76543210
7
43
0
Upper digit Lower digit
Don’t care
Don’t care
7
43
0
Upper digit Lower digit
7
0
Don’t care
MSB
LSB
7
0
Don’t care
MSB
LSB
Figure 2.6 General Register Data Formats
Rev. 2.00, 09/03, page 24 of 890