DECEQA
SC140 DSP Core Reference Manual
A-143
DECEQA
Decrement and Set T If Equal Zero
DECEQA
(AGU)
Description
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
Example
deceqa r0
Instruction Formats and Opcodes
Instruction Fields
Rx
RRRR
AGU Source/Destination Register
Operation
Assembler Syntax
Rx – 1
→
Rx; if Rx==0, then 1
→
T, else 0
→
T
DECEQA Rx
DECEQA Rx
Decrements an AGU register (Rx) and sets the T bit if the result is zero. SP cannot be used as an operand of
this instruction.
Register Address
Bit Name
Description
SR[1]
T
Set if result = 0, cleared otherwise.
Register/Memory Address
Before
After
R0
$0000 0001
$0000 0000
SR
$00E4 0000
$00E4 0002
Instruction
Words Cycles Type
Opcode
15
8
7
0
DECEQA Rx
1
1
2
1
1
1
0
R R R R
1
1
1
1
0
1
1
0
0000
N0
0100
—
1000
R0
1100
R4
0001
N1
0101
—
1001
R1
1101
R5
0010
N2
0110
—
1010
R2
1110
R6
0011
N3
0111
SP
1011
R3
1111
R7
Note:
This instruction can specify R8-R15 as operands by using a high register prefix. SP cannot be
used as an operand for this instruction.
Summary of Contents for SC140 DSP Core
Page 12: ...xii SC140 DSP Core Reference Manual ...
Page 18: ...xviii SC140 DSP Core Reference Manual ...
Page 32: ...1 6 SC140 DSP Core Reference Manual Core Architecture Features ...
Page 180: ...4 70 SC140 DSP Core Reference Manual Trace Unit Registers ...
Page 250: ...6 70 SC140 DSP Core Reference Manual Programming Rules ...
Page 314: ...7 64 SC140 DSP Core Reference Manual NOP Definition ...
Page 463: ...DI SC140 DSP Core Reference Manual A 149 15 8 7 0 DI 1 1 4 1 0 0 1 1 1 1 1 0 1 1 1 1 1 0 1 ...
Page 478: ...A 164 SC140 DSP Core Reference Manual EI ...
Page 618: ...A 304 SC140 DSP Core Reference Manual MOVES 4F s15 sssssssssssssss Signed 15 bit offset ...
Page 638: ...A 324 SC140 DSP Core Reference Manual MPYR ...
Page 746: ...A 432 SC140 DSP Core Reference Manual ZXTA x ...
Page 758: ...I 10 Index ...
Page 759: ...SC140 DSP Core Reference Manual i ...
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