Immediate-#Xx:8, #Xx:16, Or #Xx:32; Program-Counter Relative-@(D:8, Pc) Or @(D:16, Pc) - Hitachi H8S/2378, H8S/2378R Series Hardware Manual

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.
2.7.7 Program-Counter Relative—@(d:8, PC) or @(d:16, PC)
This mode can be used by the Bcc and BSR instructions. An 8-bit or 16-bit displacement
contained in the instruction code is sign-extended to 24 bits and added to the 24-bit address
indicated by the PC value to generate a 24-bit branch address. Only the lower 24 bits of this branch
address are valid; the upper 8 bits are all assumed to be 0 (H'00). The PC value to which the
displacement is added is the address of the first byte of the next instruction, so the possible
branching range is –126 to +128 bytes (–63 to +64 words) or –32766 to +32768 bytes (–16383 to
+16384 words) from the branch instruction. The resulting value should be an even number.
2.7.8 Memory Indirect—@@aa:8
This mode can be used by the JMP and JSR instructions. The instruction code contains an 8-bit
absolute address specifying a memory operand which contains a branch address. The upper bits of
the 8-bit absolute address are all assumed to be 0, so the address range is 0 to 255 (H'0000 to
H'00FF in normal mode, H'000000 to H'0000FF in advanced mode).
Rev. 1.0, 09/01, page 46 of 904
8 bits (@aa:8)
16 bits (@aa:16)
32 bits (@aa:32)
24 bits (@aa:24)
Normal Mode
H'FF00 to H'FFFF
H'0000 to H'FFFF
Advanced Mode
H'FFFF00 to H'FFFFFF
H'000000 to H'007FFF,
H'FF8000 to H'FFFFFF
H'000000 to H'FFFFFF