HD6432646 Hitachi, HD6432646 Datasheet - Page 75

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

2.5
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
Figure 2-10 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
Data Formats
General Register Data Formats
Figure 2-10 General Register Data Formats
Register Number
RnH
RnL
RnH
RnL
RnH
RnL
Data Format
MSB
7
7
7
7 6 5 4 3 2 1 0
Upper
Don’t care
Don’t care
Don’t care
4 3
Lower
LSB
0
0
0
MSB
7
7
7
7 6 5 4 3 2 1 0
Upper
Don’t care
Don’t care
Don’t care
4 3
Lower
LSB
0
0
0
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