Zilog Z80380 Manual do Utilizador descarregar pdf (Página 68)

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Z380

™

USER'S MANUAL

DC-8297-03

ZILOG

COMPARE (BYTE)

CP [A,]src src = R, RX, IM, IR, X

Operation: A – src

The source operand is compared with the accumulator and the flags are set accordingly.

The contents of the accumulator and the source are unaffected. Two’s complement

subtraction is performed.

Flags: S: Set if the result is negative; cleared otherwise

Z: Set if the result is zero; cleared otherwise

H: Set if there is a borrow from bit 4 of the result; cleared otherwise

V: Set if arithmetic overflow occurs, that is, if the operands are of different signs and the

result is of the same sign as the source; cleared otherwise

N: Set

C: Set if there is a borrow from the most significant bit of the result; cleared otherwise

Addressing Execute

Mode Syntax Instruction Format Time Note

R: CP [A,]R 10111-r- 2

RX: CP [A,]RX 11y11101 1011110w 2

IM: CP [A,]n 11111110 ——n— 2

IR: CP [A,](HL) 10111110 2+r

X: CP [A,](XY+d) 11y11101 10111110 ——d— 4+r I

Field Encodings: r: per convention

y: 0 for IX, 1 for IY

w: 0 for high byte, 1 for low byte

1 2 ... 63 64 65 66 67 68 69 70 71 72 73 ... 267 268

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Zilog Z80380 Manual do Utilizador Página 68