Motorola DSP96002 - Manual (Page 251)

MOTOROLA DSP96002 USER’S MANUAL A - 63
BTST Bit Test BTST
Operation:
S{n}
→
C
S{n}
→
C
S{n}
→
C
S{n}
→
C
S{n}
→
C
S{n}
→
C
S{n}
→
C
Assembler Syntax:
BTST #bit,X: ea
BTST #bit,X: aa
BTST #bit,X: pp
BTST #bit,Y: ea
BTST #bit,Y: aa
BTST #bit,Y: pp
BTST #bit,S
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.