Rev. 1.0, 02/00, page 30 of 1141
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 2.10 shows the data formats in general registers.
7
0
7
0
MSB
LSB
MSB
LSB
7
0
4 3
Upper digit Lower digit
Don't care
Don't care
Don't care
7
0
4 3
Upper digit Lower digit
7
0
Don't care
6
5 4
3 2
7
1 0
7
0
Don't care
6
5 4
3 2
7
1 0
Don't care
Data Format
Data type
1-bit data
1-bit data
4-bit BCD data
4-bit BCD data
Byte data
Byte data
General Register
RnH
RnL
RnH
RnL
RnH
RnL
Figure 2.10 General Register Data Formats (1)