Zilog Z80380 - Manual (Page 59)

5-25
Z380 ™
U SER ' S M ANUAL Z ILOG
DC-8297-03
ADD
ADD TO STACK POINTER (WORD)
ADD SP,src src = IM
Operation: if (XM) then begin
SP(31-0)
←
SP(31-0) + src(31-0)
end
else begin
SP(15-0)
←
SP(15-0) + src(15-0)
end
The source operand is added to the SP register and the sum is stored in the SP register. This
has the effect of allocating or allocating space on the stack. Two’s complement addition is
performed.
Flags: S: Unaffected
Z: Unaffected
H: Set if there is a carry from bit 11 of the result; cleared otherwise
V: Unaffected
N: Cleared
C: Set if there is a carry from the most significant bit of the result; cleared otherwise
Addressing Execute
Mode Syntax Instruction Format Time Note
IM: ADD SP,nn 11101101 10000010 -n(low)- -n(high) 2 I, X