Data Formats; General Register Data Formats - Renesas H8SX/1650 Hardware Manual

Section 2 CPU
2.6

Data Formats

The H8SX 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.
2.6.1

General Register Data Formats

Figure 2.12 shows the data formats in general registers.
1-bit data
1-bit data
4-bit BCD data
4-bit BCD data
Byte data
Byte data
Word data
Word data
Longword data
Rev.2.00 Jun. 28, 2007 Page 30 of 666
REJ09B0311-0200
RnH
RnL
RnH
RnL
RnH
RnL
Rn
En
ERn
15
MSB
31
MSB En
[Legend]
ERn:
General register ER
En:
General register E
Rn:
General register R
RnH:
General register RH
Figure 2.12 General Register Data Formats
7 0
7 6 5 4 3 2 1 0
7
Don't care 7 6 5 4 3 2 1 0
7 4 3 0
Upper Lower
7
Don't care Upper
7 0
MSB LSB
7
Don't care
MSB
15
MSB
0
LSB
15
16
Rn
RnL: General register RL
MSB: Most significant bit
LSB: Least significant bit
Don't care
0
Don't care
4 3 0
Lower
Don't care
0
LSB
0
LSB
0
LSB