
81
μ
PD70433
Table 17-2. Operation Code Legend
Identifier
Description
W
Word/byte specification bit (1: word, 0: byte). However, when s = 1, sign extension byte data is
specified as 16-bit operand even if W = 1.
8/16-bit general register specification bits (000 to 111)
Memory addressing specification bits (mod: 00 to 10, mem: 000 to 111)
Optional 16-bit displacement low byte
Optional 16-bit displacement high byte
16-bit displacement low byte for PC relative addition
16-bit displacement high byte for PC relative addition
3-bit immediate data
4-bit immediate data
8-bit immediate data
8-bit immediate data (1's complement of imm8)
16-bit immediate data low byte
16-bit immediate data high byte
16-bit direct address low byte
16-bit direct address high byte
Segment register specification bits (00 to 11)
Extended segment register specification bits (10 to 11)
Sign extension specification bit (1: sign extension, 0: no sign extension)
Low byte of 16-bit offset data to be loaded in PC
High byte of 16-bit offset data to be loaded in PC
Low byte of 16-bit segment data to be loaded in PS
High byte of 16-bit segment data to be loaded in PS
Low byte of 16-bit data which specifies number of bytes to be removed from stack
High byte of 16-bit data which specifies number of bytes to be removed from stack
8-bit displacement for relative addition to PC
reg, reg’
mod, mem
(disp-low)
(disp-high)
disp-low
disp-high
imm3
imm4
imm8
imm8'
imm16-low
imm16-high
addr-low
addr-high
sreg
xsreg
s
offset-low
offset-high
seg-low
seg-high
pop-value-low
pop-value-high
disp8
X
XXX
YYY
ZZZ
Operation code of an external floating point operation coprocessor