Push push register – Zilog Z80380 User Manual

Page 171

Text mode
Original mode

5-137

Z380

™

SER

ANUAL

ILOG

DC-8297-03

PUSH

PUSH REGISTER

PUSH src

src = R, RX

Operation:

if (LW) then begin

←

SP - 4

(SP)

←

src(7-0)

(SP+1)

←

src(15-8)

(SP+2)

←

src(23-16)

(SP+3)

←

src(31-24)

end

else begin

←

SP - 2

(SP)

←

src(7-0)

(SP+1)

←

src(15-8)

end

The Stack Pointer (SP) is decremented by two (by four in Long Word mode) and the source
is loaded into the memory locations addressed by the SP in ascending byte order in
ascending address memory locations. The contents of the source are unaffected.

Flags:

Unaffected

Addressing

Execute

Mode

Syntax

Instruction Format

Time

Note

PUSH R

11rr0101

3+w

RX:

PUSH RX

11y11101 11100101

3+w

Field Encodings:

rr: 00 for BC, 01 for DE, 10 for HL
y:

0 for IX, 1 for IY