Rev. 1.0, 07/01, page 14 of 372
2.3 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.
2.3.1 General Register Data Formats
Figure 2-5 shows the data formats in general registers.
70
70
MSB LSB
MSB LSB
7043
Don't care
Don't care
Don't care
7043
70
Don't care
65432710
70
Don't care
65432710
Don't care
RnH
RnL
RnH
RnL
RnH
RnL
Data Type General Register Data Format
Byte data
Byte data
4-bit BCD data
4-bit BCD data
1-bit data
1-bit data
Upper Lower
Upper Lower
Figure 2-5 General Register Data Formats (1)