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BTST
Operation:
S{n}
C
S{n}
C
S{n}
C
S{n}
C
S{n}
C
S{n}
C
S{n}
C
Description:
The nth bit of the source operand is tested and the state of the nth bit is reflected in the C condition code
bit. All memory alterable addressing modes may be used. Register Direct, Absolute Short and I/O Short
addressing may also be used.
The bit to be tested is selected by an immediate bit number 0-31. When used with the appropriate rotate
instructions, this instruction is useful for serial to parallel conversions.
If the system stack register SSH is specified as a source operand, the system stack pointer SP is postdec-
remented by 1 after SSH is read.
CCR Condition Codes:
C
- Set if bit tested is set. Cleared otherwise.
V
- Not affected.
Z
- Not affected.
N
- Not affected.
I
- Not affected.
LR
- Not affected.
–
R
- Not affected.
A
- Not affected.
ER Status Bits: Not affected.
IER Flags: Not affected.
MOTOROLA
Bit Test
Assembler Syntax:
BTST
BTST
BTST
BTST
BTST
BTST
BTST
DSP96002 USER'S MANUAL
#bit,X: ea
#bit,X: aa
#bit,X: pp
#bit,Y: ea
#bit,Y: aa
#bit,Y: pp
#bit,S
BTST
A - 63
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