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APPENDIX A INSTRUCTION MNEMONIC (IN ALPHABETICAL ORDER)
Table A-1. Instruction Mnemonic (in alphabetical order) (2/7)
Instruction
Mnemonic
Operand
Format
CY
OV
S
Z
SAT
Instruction Function
DIVH
reg1, reg2
I
–
*
*
*
–
Signed divide. Divides the word data of reg2 by
the lower half-word data of reg1, and stores the
quotient to reg2.
EI
–
X
–
–
–
–
–
Enables maskable interrupt. Resets the ID flag
of the PSW to 0 and enables the acknowledge-
ment of maskable interrupts at the beginning of
next instruction.
HALT
–
X
–
–
–
–
–
CPU halt. Stops the operating clock of the CPU
and places the CPU in the HALT mode.
JARL
disp22, reg2
V
–
–
–
–
–
Jump and register link. Saves the current PC
value plus 4 to general register reg2, adds a 22-
bit displacement, sign-extended to word length,
to the current PC value, and transfers control to
the PC. Bit 0 of the 22-bit displacement is
masked to 0.
JMP
[reg1]
I
–
–
–
–
–
Register indirect unconditional branch. Trans-
fers control to the address specified by reg1. Bit
0 of the address is masked to 0.
JR
disp22
V
–
–
–
–
–
Unconditional branch. Adds a 22-bit displace-
ment, sign-extended to word length, to the
current PC value, and transfers control to the
PC. Bit 0 of the 22-bit displacement is masked
to 0.
LD.B
disp16 [reg1], reg2
VII
–
–
–
–
–
Byte load. Adds the data of reg1 to a 16-bit
displacement, sign-extended to word length, to
generate a 32-bit address. Byte data is read
from the generated address, sign-extended to
word length, and then stored to reg2.
LD.H
disp16 [reg1], reg2
VII
–
–
–
–
–
Half-word load. Adds the data of reg1 to a 16-bit
displacement, sign-extended to word length, to
generate a 32-bit address. Half-word data is
read from this 32-bit address with its bit 0
masked to 0, sign-extended to word length, and
stored to reg2.
LD.W
disp16 [reg1], reg2
VII
–
–
–
–
–
Word load. Adds the data of reg1 to a 16-bit
displacement, sign-extended to word length, to
generate a 32-bit address. Word data is read
from this 32-bit address with bits 0 and 1 masked
to 0, and stored to reg2.