Renesas H8SX/1650, Hardware Manual

Page: 52 / 692

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