Fujitsu CM71-00101-5E 2.2 Bit Order and Byte Order

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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.
■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 space
12H
34H
56H
78H
0000 0000H
1234 5678H
1234 5679H
1234 567AH
1234 567BH
FFFF FFFFH
R10 12345678H
LD @R10,R0
3124231615 870
R0 12H34H56H78H