Samsung KS57C2308 Manual page 111

KS57C2308/P2308/C2316/P2316
BTSF
— Bit Test and Skip on False
BTSF dst.b
Operation: Operand
DA.b
mema.b
memb.@L
@H+DA.b
Description: The specified bit within the destination operand is tested. If it is a "0", the BTSF instruction skips
the instruction which immediately follows it; otherwise the instruction following the BTSF is
executed. The destination bit value is not affected.
Operand
DA.b
mema.b
memb.@L
@H + DA.b
*
mema.b
Examples: 1. If RAM bit location 30H.2 is set to "0", the following instruction sequence will cause the
program to continue execution from the instruction identified as LABEL2:
BTSF 30H.2
RET
JP
2. You can use BTSF in the same way to test a port pin address bit:
BTSF P2.0
RET
JP
Test specified memory bit and skip if bit equals "0"
Binary Code
1 1 b1
a7 a6 a5
* 1 1 1
1 1 1
0 1 0
1 1 1
0 0 b1
Second Byte
1 0 b1
1 1 b1
LABEL2
LABEL3
Operation Summary
b0 0 0 1
a4 a3 a2 a1 a0
1 1 0 0
1 1 0 0
0 a5 a4 a3 a2
1 1 0 0
b0 a3 a2 a1 a0
b0 a3 a2 a1 a0 FB0H–FBFH
b0 a3 a2 a1 a0 FF0H–FFFH
; If 30H.2 = "0", then skip
; If 30H.2 = "1", return
; If P2.0 = "0", then skip
; If P2.0 = "1", then return
SAM47 INSTRUCTION SET
Bytes
2
2
2
2
Operation Notation
0 Skip if DA.b = 0
0 Skip if mema.b = 0
0 Skip if [memb.7–2 + L.3-2].
[L.1–0] = 0
0 Skip if [H + DA.3–0].b = 0
Bit Addresses
Cycles
2 + S
2 + S
2 + S
2 + S
5-37