Chapter 14 Instruction Set; Operation; Operand Identifiers And Writing Methods - NEC UPD789026 Series User Manual

This chapter lists the instruction set of the µ PD789026 Subseries. For the details of the operation and machine
language (instruction code) of each instruction, refer to 78K/0S Series User's Manual     Instruction (U11047E).

14.1 Operation

14.1.1 Operand identifiers and writing methods

Operands are written in "Operand" column of each instruction in accordance with the writing method of the
instruction operand identifier (refer to the assembler specifications for detail). When there are two or more writing
methods, select one of them. Alphabetic letters in capitals and symbols, #, !, $, and [ ] are key words and are written
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, write an appropriate numeric value or a label. When using a label, be sure to
write the #, !, $ and [ ] symbols.
For operand register identifiers, r and rp, either functional names (X, A, C, etc.) or absolute names (names in
parentheses in the table below, R0, R1, R2, etc.) can be used.
Identifier
r
rp
sfr
www.DataSheet4U.com
saddr
saddrp
addr16
addr5
word
byte
bit
Remark

CHAPTER 14 INSTRUCTION SET

Table 14-1. Operand Identifiers and Writing Methods
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
FE20H to FF1FH Immediate data or labels
FE20H to FF1FH Immediate data or labels (even addresses only)
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)
16-bit immediate data or label
8-bit immediate data or label
3-bit immediate data or label
See Table 3-4 for symbols of special function registers.
Writing Method
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