Excalibur electronic A-MNL-NIOSPROG-01.1 用户手册
Altera Corporation
103
32323232
32-Bit Instruction Set
2
3
2
-B
it In
st
st
ru
ctio
n
n
Se
t
t
TRET
Trap Return
Operation:
PC
← (RA << 1)
STATUS
← ISTATUS
Assembler Syntax:
TRET %ra
Example:
TRET %o7 ; return from TRAP
Description:
Execution is transferred to the address given by (RA << 1). The value written in
%o7 by TRAP is suitable for use as a return-address without modification.
%o7 by TRAP is suitable for use as a return-address without modification.
The value in ISTATUS is copied into the STATUS register (this restores the pre-
TRAP register window, because CWP is part of STATUS).
Condition Codes:
Flags: Unaffected
Instruction Format:
Rw
Instruction Fields:
A = Register index of operand RA
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
1
1
1
1
0
1
1
1
0
A
N
V
Z
C
−
−
−
−