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Rev. 1.00, 05/04, page 42 of 544
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 an 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.