Fujitsu MB91260B Series Hardware Manual page 471

APPENDIX D Notes When Little Endian Area Is Used
■ Assembler (fasm911)
For programming using the assembler language of FR family, operating suggestions relating to the little
endian area are shown below.
●
Section
The little endian area is used mainly for exchanging data to the little endian CPU. Therefore, please define
the little endian area as a data section where an initial value does not exist.
When specifying a code, a stack, or a data section with an initial value to the little endian area, the access
operation by MB91260B series cannot be guaranteed.
[Example]
/* Correct section definition in the little endian area */
Little_Word:
Little_Half:
Little_Byte:
●
Data access
When accessing to the little endian area data, coding can be done to the value of the data without
considering endians. However, please access to the little endian area data by using the same size access as
the data size.
[Example]
LDI
LDI
LDI
LDI
LDI
LDI
/* Use a ST instruction (or a LD instruction, etc.) for 32-bit data access */
ST
/* Use a STH instruction (or a LDH instruction, etc.) for 16-bit data access */
STH
456
.SECTION Little_Area, DATA, ALIGN=4
.RES.W 1
.RES.H 1
.RES.B 1
#0x01020304, r0
#Little_Word, r1
#0x0102, r2
#Little_Half, r3
#0x01, r4
#Little_Byte, r5
r0, @r1
r2, @r3