Specifications

Instruction Fields
A = Register index of operand rA
B = Register index of operand rB
C = Register index of operand rC
Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
A B C 0x39
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0x39 0 0x3a
subi
Instruction
subtract immediate
Operation
rB ← rA – σ(IMMED)
Assembler Syntax
subi rB, rA, IMMED
Example
subi r8, r8, 4
Description
Sign-extends the immediate value IMMED to 32 bits, subtracts
it from the value of rA and then stores the result in rB.
Usage
The maximum allowed value of IMMED is 32768. The
minimum allowed value is
–32767.
Pseudo-instruction
subi is implemented as addi rB, rA, -IMMED
sync
Instruction
memory synchronization
Operation
None
Assembler Syntax
sync
Example
sync
Description
Forces all pending memory accesses to complete before
allowing execution of subsequent instructions. In processor
cores that support in-order memory accesses only, this instruc‐
tion performs no operation.
Exceptions
None
8-80
subi
NII51017
2015.04.02
Altera Corporation
Instruction Set Reference
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