HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 33

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

4. Register Indirect with Post-Increment or Pre-Decrement—@Rn+ or @–Rn:
5. Absolute Address—@aa:8 or @aa:16: The instruction specifies the absolute address of the
6. Immediate—#xx:8 or #xx:16: The second byte (#xx:8) or the third and fourth bytes (#xx:16)
7. Program-Counter Relative—@(d:8, PC): This mode is used in the Bcc and BSR
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operand in memory.
The absolute address may be 8 bits long (@aa:8) or 16 bits long (@aa:16). The MOV.B and bit
manipulation instructions can use 8-bit absolute addresses. The MOV.B, MOV.W, JMP, and
JSR instructions can use 16-bit absolute addresses.
For an 8-bit absolute address, the upper 8 bits are assumed to be 1 (H'FF). The address range is
H'FF00 to H'FFFF (65280 to 65535).
of the instruction code are used directly as the operand. Only MOV.W instructions can be used
with #xx:16.
The ADDS and SUBS instructions implicitly contain the value 1 or 2 as immediate data. Some
bit manipulation instructions contain 3-bit immediate data in the second or fourth byte of the
instruction, specifying a bit number.
instructions. An 8-bit displacement in byte 2 of the instruction code is sign-extended to 16 bits
and added to the program counter contents to generate a branch destination address, and the PC
contents to be added are the start address of the next instruction, so that the possible branching
range is –126 to +128 bytes (–63 to +64 words) from the branch instruction. The displacement
should be an even number.
Register indirect with post-increment—@Rn+
The @Rn+ mode is used with MOV instructions that load registers from memory.
The register field of the instruction specifies a 16-bit general register containing the address
of the operand. After the operand is accessed, the register is incremented by 1 for MOV.B
or 2 for MOV.W, and the result of the addition is stored in the register. For MOV.W, the
original contents of the 16-bit general register must be even.
Register indirect with pre-decrement—@–Rn
The @–Rn mode is used with MOV instructions that store register contents to memory.
The register field of the instruction specifies a 16-bit general register which is decremented
by 1 or 2 to obtain the address of the operand in memory. The register retains the
decremented value. The size of the decrement is 1 for MOV.B or 2 for MOV.W. For
MOV.W, the original contents of the register must be even.
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