Excalibur electronic A-MNL-NIOSPROG-01.1 用户手册
104
Altera Corporation
32-Bit Instruction Set
WRCTL
Write Control Register
Operation:
CTLk
← RA
Assembler Syntax:
WRCTL %rA
Example:
Not preceded by PFX:
WRCTL %g7 ; writes %g7 to STATUS reg
NOP ; required
Preceded by PFX:
PFX 1
WRCTL %g7 ; writes %g7 to ISTATUS reg
Description:
Not preceded by PFX:
Loads the STATUS register with RA. WRTCL to STATUS must be followed by a
Loads the STATUS register with RA. WRTCL to STATUS must be followed by a
NOP instruction.
Preceded by PFX:
Preceded by PFX:
Writes the value in RA to the machine-control register selected by K. See the
programmer’s model for a list of the machine-control registers and their indices.
programmer’s model for a list of the machine-control registers and their indices.
Condition Codes:
If the target of WRCTL is the STATUS register, then the condition-code flags are
directly set by the WRCTL operation from bits RA[3..0]. For any other WRCTL
directly set by the WRCTL operation from bits RA[3..0]. For any other WRCTL
target register, the condition codes are 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
1
1
0
0
0
A