Datasheet

Section 2 CPU
Rev. 2.00 Sep. 23, 2005 Page 15 of 444
REJ09B0068-0200
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 to 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.
7 0
7
0
MSB LSB
MSB LSB
704 3
Don't care
Don't care
Don't care
7 04
3
70
Don't care
6543271
0
7
0
Don't care
65432710
Don't care
RnH
RnL
RnH
RnL
RnH
RnL
Data Type General Register Data Format
1-bit data
1-bit data
4-bit BCD data
4-bit BCD data
Byte data
Byte data
Upper Lower
Upper Lower
Figure 2.5 General Register Data Formats (1)