Fujitsu CM71-00101-5E User Manual
10
CHAPTER 2 MEMORY ARCHITECTURE
2.2
Bit Order and Byte Order
This section describes the order in which three types of data, 8, 16, and 32 bits, are
placed in the memory in the FR family.
In the FR family, the bit number increases approaching the MSB, and the byte number
increases approaching the lowest address value.
placed in the memory in the FR family.
In the FR family, the bit number increases approaching the MSB, and the byte number
increases approaching the lowest address value.
■
Bit Order and Byte Order
Bit order in the general-purpose register is that the larger numbers are placed in the vicinity of the MSB
while the smaller numbers are near the LSB. Byte order configuration requires the upper data to be placed
in the smaller address memory, while the lower data are placed in the larger address memory.
Figure 2.2-1 illustrates the bit order and byte order in the FR family.
Figure 2.2-1 Bit Order and Byte Order
Bit order
Memory
s
p
a
ce
12
H
3
4
H
56
H
7
8
H
0000 0000
H
12
3
4 567
8
H
12
3
4 5679
H
12
3
4 567A
H
12
3
4 567B
H
FFFF FFFF
H
R10 12
3
4567
8
H
LD @R10,R0
3
1
242
3
1615
8
7
0
R0
12
H
3
4
H
56
H
7
8
H