CHAPTER 19 INSTRUCTION SET
This chapter lists the instruction set of the µPD789426, 789436, 789446, and 789456 Subseries. For the details
of the operation and machine language (instruction code) of each instruction, refer to 78K/0S Series Instructions
User’s Manual (U11047E).
19.1 Operation
19.1.1 Operand identifiers and description methods
Operands are described in “Operand” column of each instruction in accordance with the description method of the
instruction operand identifier (refer to the assembler specifications for detail). When there are two or more
description methods, select one of them. Alphabetic letters in capitals and symbols, #, !, $, and [ ] are key words
and are described as they are. Each symbol has the following meaning.
• #: Immediate data specification
• !: Absolute address specification
• $: Relative address specification
• [ ]: Indirect address specification
In the case of immediate data, describe an appropriate numeric value or a label. When using a label, be sure to
describe the #, !, $ and [ ] symbols.
For operand register identifiers, r and rp, either functional names (X, A, C, etc.) or absolute names (names in
parenthesis in the table below, R0, R1, R2, etc.) can be used for description.
Table 19-1. Operand Identifiers and Description Methods
Identifier
Description Method
r
X (R0), A (R1), C (R2), B (R3), E (R4), D (R5), L (R6), H (R7)
AX (RP0), BC (RP1), DE (RP2), HL (RP3)
Special-function register symbol
rp
sfr
saddr
FE20H to FF1FH Immediate data or labels
saddrp
FE20H to FF1FH Immediate data or labels (even addresses only)
addr16
addr5
0000H to FFFFH Immediate data or labels (only even addresses for 16-bit data transfer instructions)
0040H to 007FH Immediate data or labels (even addresses only)
word
byte
bit
16-bit immediate data or label
8-bit immediate data or label
3-bit immediate data or label
Remark See Table 3-4 Special Function Register List for symbols of special function registers.
User’s Manual U15075EJ1V0UM00
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NEC [ NEC ]
