Zilog Z80380 - Manual (Page 192)

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Z380 ™
U SER ' S M ANUAL
DC-8297-03
Z ILOG
RST
RESTART
RST address
Operation: if (XM) then begin
SP
←
SP - 4
(SP)
←
PC(7-0)
(SP+1)
←
PC(15-8)
(SP+2)
←
PC(23-16)
(SP+3)
←
PC(31-24)
end
else begin
SP
←
SP - 2
(SP)
←
PC(7-0)
(SP+1)
←
PC(15-8)
end
PC
←
address
The current Program Counter (PC) is pushed onto the stack and the PC is loaded with a
constant address encoded in the instruction. Execution then begins at this address. The
restart instruction allows for a call to one of eight fixed locations as shown in the table below.
The table also indicates the encoding of the address used in the instruction encoding. (The
address is in hexadecimal, the encoding in binary.)
Address t encoding
00000000h 000
00000008h 001
00000010h 010
00000018h 011
00000020h 100
00000028h 101
00000030h 110
00000038h 111
Flags: S: Unaffected
Z: Unaffected
H: Unaffected
V: Unaffected
N: Unaffected
C: Unaffected
Addressing Execute
Mode Syntax Instruction Format Time Note
RST address 11-t-111 4+w X
Field Encodings: 000 for 00h, 001 for 08h, 010 for 10h, 011 for 18h,
100 for 20h, 101 for 28h, 110 for 30h, 111 for 38h