INSTRUCTION SET
S3C80A5B
6-18
BCP
—
Bit Compare
BCP
dst,src.b
Operation:
dst(0)
←
src(b)
The specified bit of the source is compared to (subtracted from) bit zero (LSB) of the destination.
The zero flag is set if the bits are the same; otherwise it is cleared. The contents of both operands
are unaffected by the comparison.
Flags:
C:
Unaffected.
Z:
Set if the two bits are the same; cleared otherwise.
S:
Cleared to "0".
V:
Undefined.
D:
Unaffected.
H:
Unaffected.
Format:
Bytes
Cycles
Opcode
(Hex)
Addr Mode
dst src
opc
dst | b | 0
src
3
6
17
r0
Rb
NOTE
: In the second byte of the instruction format, the destination address is four bits, the bit address 'b'
is three bits, and the LSB address value is one bit in length.
Example:
Given: R1 = 07H and register 01H = 01H:
BCP
R1,01H.1
→
R1 = 07H, register 01H = 01H
If destination working register R1 contains the value 07H (00000111B) and the source register 01H
contains the value 01H (00000001B), the statement "BCP R1,01H.1" compares bit one of the
source register (01H) and bit zero of the destination register (R1). Because the bit values are not
identical, the zero flag bit (Z) is cleared in the FLAGS register (0D5H).