Excalibur electronic A-MNL-NIOSPROG-01.1 用户手册
94
Altera Corporation
32-Bit Instruction Set
ST8s
Store 8-bit Data To Memory (Static Byte-Offset Address)
Operation:
Not preceded by PFX:
bn
Mem32[align32(RA)]
←
bn
R0 where n = IMM2
Preceded by PFX:
bn
Mem32[align32(RA + (
σ(K) × 4))] ←
bn
R0 where n = IMM2
Assembler Syntax:
ST8s [%rA],%r0,IMM2
Example:
Not preceded by PFX:
MOVI %g4,12
ST8s [%g4],%r0,3 ; store high byte of %r0 to mem[15]
Preceded by PFX:
PFX 9
ST8s [%g4],%r0,2 ; store byte 2 of %r0 to
; mem[%g4 + 36 + 2]
Description:
Not preceded by PFX:
Stores one of the four bytes of %r0 to memory at the byte-address given by
Stores one of the four bytes of %r0 to memory at the byte-address given by
(RA[31..2] plus IMM2). The two bits RA[1..0] are ignored. IMM2 selects which
byte of %r0 is stored (byte 3 is most significant).
byte of %r0 is stored (byte 3 is most significant).
ST8s may be used in combination with FILL8 to implement a byte-store operation
to a byte-offset from a word-aligned base pointer. Given a byte held in bits 7..0 of
any register %rX, the following sequence writes this byte to memory at the byte-
any register %rX, the following sequence writes this byte to memory at the byte-
address given by (RA + Y ) (RA presumed to hold a word-aligned pointer):
FILL8 %r0,%rX
PFX Y >> 2
ST8s [%rA],%r0,Y & 3
Preceded by PFX:
A 13-bit signed, byte-scaled offset is formed by concatenating K with IMM2. This
offset (K : IMM2) is sign-extended to 32 bits and used as the byte-offset for the
offset (K : IMM2) is sign-extended to 32 bits and used as the byte-offset for the
ST-operation.
Condition Codes:
Flags: Unaffected
Instruction Format:
Ri2u
Instruction Fields:
A = Register index of operand RA
IMM2 = 2-bit immediate value
IMM2 = 2-bit immediate value
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
1
1
0
1
1
0
0
IMM2
A
N
V
Z
C
−
−
−
−