HD64F2168 Datasheet, PDF (68/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

2.5 Data Formats
The H8S/2000 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
Figure 2.9 shows the data formats of general registers.
Data Type
1-bit data
1-bit data
Register Number
RnH
Data Image
7
0
7 6 5 4 3 2 10
Don't care
7
0
RnL
Don't care
7 6 5 4 3 2 10
4-bit BCD data
RnH
7
43
0
Upper
Lower
Don't care
4-bit BCD data
RnL
Don't care
7
43
0
Upper
Lower
Byte data
Byte data
RnH
7
MSB
0
Don't care
LSB
7
0
RnL
Don't care
MSB
LSB
Figure 2.9 General Register Data Formats (1)
Rev. 3.00, 03/04, page 28 of 830