Computer Hardware User's Guide

POP Pop Integer
13-194
Syntax POP dst
Operation *SP–– → dst
Operands dst register (R n , 0 ≤ n ≤ 27)
Opcode
31 24 23 16 8 7 015
000 01 0
1 01 dst 10 000 000 00 00 000 000
Description The top of the current system stack is popped and loaded into the dst register
(32 LSBs). The top of the stack is assumed to be a signed integer. The POP
is performed with a postdecrement of the stack pointer. The exponent bits of
an extended-precision register (R7–R0) are left unmodified.
Cycles 1
Status Bits These condition flags are modified only if the destination register is R7–R0.
LUF Unaffected
LV Unaffected
UF 0
N 1 if a negative result is generated; 0 otherwise
Z 1 if a 0 result is generated; 0 otherwise
V 0
C Unaffected
OVM Operation is not affected by OVM bit value.
Example POP R3
Before Instruction After Instruction
R3 00 0000 12DA R3 00 FFFF 0DA4
SP 809856 SP 809855
LUF 0 LUF 0
LV 0 LV 0
UF 0 UF 0
N 0 N 1
Z 0 Z 0
V 0 V 0
C 0 C 0
Data memory
809856h FFFF0DA4 809856h FFFF0DA4
4,826 –62,044
–62,044
–62,044
Mode Bit