Absolute Address-@Aa:8, @Aa:16, @Aa:24, Or @Aa:32; Immediate-#Xx:8, #Xx:16, Or #Xx:32; Table 2.12 Absolute Address Access Ranges - Renesas H8S/2158 User Manual

Section 2 CPU
Register Indirect with Pre-Decrement—@-ERn: The value 1, 2, or 4 is subtracted from an
address register (ERn) specified by the register field in the instruction code, and the result
becomes the address of a memory operand. The result is also stored in the address register. The
value subtracted is 1 for byte access, 2 for word access, and 4 for longword access. For word or
longword transfer instructions, the register value should be even.
2.7.5 Absolute Address—@aa:8, @aa:16, @aa:24, or @aa:32
The instruction code contains the absolute address of a memory operand. The absolute address
may be 8 bits long (@aa:8), 16 bits long (@aa:16), 24 bits long (@aa:24), or 32 bits long
(@aa:32). Table 2.12 indicates the accessible absolute address ranges.
To access data, the absolute address should be 8 bits (@aa:8), 16 bits (@aa:16), or 32 bits
(@aa:32) long. For an 8-bit absolute address, the upper 16 bits are all assumed to be 1 (H'FFFF).
For a 16-bit absolute address, the upper 16 bits are a sign extension. For a 32-bit absolute address,
the entire address space is accessed.
A 24-bit absolute address (@aa:24) indicates the address of a program instruction. The upper 8
bits are all assumed to be 0 (H'00).

Table 2.12 Absolute Address Access Ranges

Absolute Address
Data address
Program instruction
address
2.7.6 Immediate—#xx:8, #xx:16, or #xx:32
The 8-bit (#xx:8), 16-bit (#xx:16), or 32-bit (#xx:32) immediate data contained in a instruction
code can be used directly as an operand.
The ADDS, SUBS, INC, and DEC instructions implicitly contain immediate data in their
instruction codes. Some bit manipulation instructions contain 3-bit immediate data in the
instruction code, specifying a bit number. The TRAPA instruction contains 2-bit immediate data
in its instruction code, specifying a vector address.
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REJ09B0286-0300
Normal Mode
8 bits (@aa:8) H'FF00 to H'FFFF
16 bits (@aa:16) H'0000 to H'FFFF
32 bits (@aa:32)
24 bits (@aa:24)
Advanced Mode
H'FFFF00 to H'FFFFFF
H'000000 to H'007FFF,
H'FF8000 to H'FFFFFF
H'000000 to H'FFFFFF