© 2000 Scenix Semiconductor, Inc. All rights reserved.
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SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75
16.0 INSTRUCTION SET SUMMARY TABLE
Table 16-1 lists all of the instructions, organized by cate-
gory. For each instruction, the table shows the instruction
mnemonic (as written in assembly language), a brief
description of what the instruction does, the number of
instruction cycles required for execution, the binary
opcode, and the status bits affected by the instruction.
The “Cycles” column typically shows a value of 1, which
means that the overall throughput for the instruction is
one per clock cycle. In some cases, the exact number of
cycles depends on the outcome of the instruction (such
as the test-and-skip instructions) or the clocking mode
(Compatible or Turbo). In those cases, all possible num-
bers of cycles are shown in the table.
The instruction execution time is derived by dividing the
oscillator frequency by either one (Turbo mode) or four
(Compatible mode). The divide-by factor is selected
through the FUSE Word register.
Table 16-1. The SX Instruction Set
Mnemonic,
Operands
Description
Cycles
(Compatible)
Cycles
(Turbo)
Opcode
Bits
Affected
Logical Operations
AND fr, W
AND of fr and W into fr (fr = fr & W)
1
1
0001 011f ffff
Z
AND W, fr
AND of W and fr into W (W = W & fr)
1
1
0001 010f ffff
Z
AND W,#lit
AND of W and Literal into W (W = W & lit)
1
1
1110 kkkk kkkk
Z
NOT fr
Complement of fr into fr (fr = fr ^ FFh)
1
1
0010 011f ffff
Z
OR fr,W
OR of fr and W into fr (fr = fr | W)
1
1
0001 001f ffff
Z
OR W,fr
OR of W and fr into fr (W = W | fr)
1
1
0001 000f ffff
Z
OR W,#lit
OR of W and Literal into W (W = W | lit)
1
1
1101 kkkk kkkk
Z
XOR fr,W
XOR of fr and W into fr (fr = fr ^ W)
1
1
0001 101f ffff
Z
XOR W,fr
XOR of W and fr into W (W = W ^ fr)
1
1
0001 100f ffff
Z
XOR W,#lit
XOR of W and Literal into W (W = W ^ lit)
1
1
1111 kkkk kkkk
Z
Arithmetic and Shift Operations
ADD fr,W
Add W to fr (fr = fr + W); carry bit is added if CF
bit in FUSEX register is cleared to 0
1
1
0001 111f ffff
C, DC, Z
ADD W,fr
Add fr to W (W = W + fr); carry bit is added if CF
bit in FUSEX register is cleared to 0
1
1
0001 110f ffff
C, DC, Z
CLR fr
Clear fr (fr = 0)
1
1
0000 011f ffff
Z
CLR W
Clear W (W = 0)
1
1
0000 0100 0000
Z
CLR !WDT
Clear Watchdog Timer, clear prescaler if as-
signed to the Watchdog (TO = 1, PD = 1)
1
1
0000 0000 0100
TO, PD
DEC fr
Decrement fr (fr = fr - 1)
1
1
0000 111f ffff
Z
DECSZ fr
Decrement fr and Skip if Zero (fr = fr - 1 and skip
next instruction if result is zero)
1 or
2 (skip)
1 or
2 (skip)
0010 111f ffff
none
INC fr
Increment fr (fr = fr + 1)
1
1
0010 101f ffff
Z
INCSZ fr
Increment fr and Skip if Zero (fr = fr + 1 and skip
next instruction if result is zero)
1 or
2 (skip)
1 or
2 (skip)
0011 111f ffff
none
RL fr
Rotate fr Left through Carry (fr = << fr)
1
1
0011 011f ffff
C
RR fr
Rotate fr Right through Carry (fr = >> fr)
1
1
0011 001f ffff
C
SUB fr,W
Subtract W from fr (fr = fr - W); complement of
the carry bit is subtracted if CF bit in FUSEX
register is cleared to 0
1
1
0000 101f ffff
C, DC, Z
SWAP fr
Swap High/Low Nibbles of fr (fr = <> fr)
1
1
0011 101f ffff
none
