NEC switch - Description of Operation Column; Description of Flag Operation Column

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CHAPTER 15 INSTRUCTION SET

User’s Manual U12978EJ3V0UD

201

15.1.2 Description of “operation” column

A: A register; 8-bit accumulator

X: X register

B: B register

C: C register

D: D register

E: E register

H: H register

L: L register

AX: AX register pair; 16-bit accumulator

BC: BC register pair

DE: DE register pair

HL: HL register pair

PC: Program counter

SP: Stack pointer

PSW: Program status word

CY: Carry flag

AC: Auxiliary carry flag

Z: Zero flag

IE: Interrupt request enable flag

NMIS: Flag indicating non-maskable interrupt servicing in progress

( ): Memory contents indicated by address or register contents in parenthesis

, x

: Higher 8 bits and lower 8 bits of 16-bit register

∧: Logical product (AND)

∨: Logical sum (OR)

V: Exclusive logical sum (exclusive OR)



: Inverted data

addr16: 16-bit immediate data or label

jdisp8: Signed 8-bit data (displacement value)

15.1.3 Description of “flag operation” column

(Blank): Unchanged

0: Cleared to 0

1: Set to 1

x: Set/cleared according to the result

R: Previously saved value is restored