Datasheet

Section 2 CPU
Rev. 4.00 Jun 06, 2006 page 57 of 1004
REJ09B0301-0400
Immediate—#xx:8, #xx:16, or #xx:32: The instruction contains 8-bit (#xx:8), 16-bit (#xx:16), or
32-bit (#xx:32) immediate data as an operand.
The ADDS, SUBS, INC, and DEC instructions contain immediate data implicitly. 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.
Program-Counter Relative—@(d:8, PC) or @(d:16, PC): This mode is used in the Bcc and
BSR instructions. An 8-bit or 16-bit displacement contained in the instruction is sign-extended and
added to the 24-bit PC contents to generate a 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.
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. This memory
operand contains a branch address. The upper bits of the 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). In normal mode the memory operand is a word operand and the branch address
is 16 bits long. In advanced mode the memory operand is a longword operand, the first byte of
which is assumed to be all 0 (H'00).
Note that the first part of the address range is also the exception vector area. For further details,
refer to section 4, Exception Handling.
(a) Normal Mode (b) Advanced Mode
Branch address
Specified
by @aa:8
Specified
by @aa:8
Reserved
Branch address
Figure 2.13 Branch Address Specification in Memory Indirect Mode