PUSH Floating-Point Value
PUSHF
13-197
Assembly Language Instructions
Syntax
PUSHF
src
Operation
src
→
*++SP
Operands
src register (Rn, 0
≤
n
≤
7)
Opcode
31
24 23
16
8 7
0
15
0 0 0
0 1
1
1
1
1
src
0
0 1
0 0 0 0
0 0 0 0
0 0 0 0 0 0 0 0
Description
The contents of the
src register (32 MSBs) are pushed on the current system
stack. The
src is assumed to be a floating-point number. The PUSH is per-
formed with a preincrement of the stack pointer. The eight LSBs of the mantis-
sa are not saved. (Note the difference in R2 and the value on the stack in the
example below.)
Cycles
1
Status Bits
LUF
Unaffected
LV
Unaffected
UF
Unaffected
N
Unaffected
Z
Unaffected
V
Unaffected
C
Unaffected
OVM
Operation is not affected by OVM bit value.
Example
PUSHF R2
Before Instruction
After Instruction
R2
02 5C12 8081
R2
02 5C12 8081
SP
809801
SP
809802
LUF
0
LUF
0
LV
0
LV
0
UF
0
UF
0
N
0
N
0
Z
0
Z
0
V
0
V
0
C
0
C
0
Data memory
809802h
0
809802h
025C1280
6.8700
6.8700
6.8700
Mode Bit