Data Formats; General Register Data Formats - Renesas H8S Series Hardware Manual

2.5

Data Formats

The 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 2-7 shows the data formats in general registers.
Data Type
1-bit data
1-bit data
4-bit BCD data
4-bit BCD data
Byte data
Byte data
Rev.6.00 Oct.28.2004 page 30 of 1016
REJ09B0138-0600H
Register Number Data Format
RnH
7
7 6 5 4 3 2 1 0
RnL
RnH
7
RnL
RnH
7
MSB
RnL
Figure 2-7 General Register Data Formats
0
7
Don't care 7 6 5 4 3 2 1 0
4 3
0
Upper Lower
7
Don't care Upper
0
LSB
7
Don't care
MSB
Don't care
0
Don't care
4 3 0
Lower
Don't care
0
LSB