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61
MB90230 Series
I
INSTRUCTIONS (412 INSTRUCTIONS)
Table 1 Description of Instruction Table
Item
Description
Mnemonic
Upper-case letters and symbols: Described directry in assembly code
Lower-case letters: Replaced when described in assembly code
Numbers after lower-case letters: Indicates the bit width within the code
#
Indicates the number of bytes
~
Indicates the number of cycles
See Table 4 for details about meanings of letters in items.
B
Indicates the compensation value for calculating the number of actual cycles during
execution of instruction.
The number of actual cycles during execution of instruction is summed with the value in
the “cycles” column.
Operation
Indicates operation of instruction.
LH
Indicates special operations involving the bits 15 through 08 of the accumulator.
Z: Transfers “0”
X: Extends before transferring
—: No transfer
AH
Indicates special operations involving the high-order 16 bits in the accumulator.
*: Transfers from AL to AH
—: No transfer
Z: Transfers 00
H
to AH.
X: Transfers 00
H
or FF
H
to AH by extending AL
I
Indicates the status of each of the following flags: I (interrupt enable), S (stack), T (sticky
bit), N (negative), Z (zero), V (overflow), and C (carry).
*: Changes due to execution of instruction.
—: No change.
S: Set by execution of instruction.
R: Reset by execution of instruction.
S
T
N
Z
V
C
RMW
Indicates whether the instruction is a read-modify-write instruction (a single instruction
that reads data from memory, etc., processes the data, and then writes the result to
memory.).
*: Instruction is a read-modify-write instruction
—: Instruction is not a read-modify-write instruction
Note: Cannot be used for addresses that have different meanings depending on
whether they are read or written.