KS57C2308/P2308/C2316/P2316
SAM47 INSTRUCTION SET
5-39
BTST
— Bit Test and Skip on True
BTST
dst.b
Operation:
Operand
Operation Summary
Bytes
Cycles
C
Test carry bit and skip if set (= "1")
1
1 + S
DA.b
Test specified bit and skip if memory bit is set
2
2 + S
mema.b
2
2 + S
memb.@L
2
2 + S
@H+DA.b
2
2 + S
Description:
The specified bit within the destination operand is tested. If it is "1", the instruction that
immediately follows the BTST instruction is skipped; otherwise the instruction following the BTST
instruction is executed. The destination bit value is not affected.
Operand
Binary Code
Operation Notation
C
1
1
0
1
0
1
1
1
Skip if C = 1
DA.b
1
1
b1
b0
0
0
1
1
Skip if DA.b = 1
a7
a6
a5
a4
a3
a2
a1
a0
mema.b
*
1
1
1
1
1
0
0
1
Skip if mema.b = 1
memb.@L
1
1
1
1
1
0
0
1
Skip if [memb.7–2 + L.3–2].
[L.1–0] = 1
0
1
0
0
a5
a4
a3
a2
@H+DA.b
1
1
1
1
1
0
0
1
Skip if [H + DA.3–0].b = 1
0
0
b1
b0
a3
a2
a1
a0
Second Byte
Bit Addresses
*
mema.b
1
0
b1
b0
a3
a2
a1
a0
FB0H–FBFH
1
1
b1
b0
a3
a2
a1
a0
FF0H–FFFH
Examples:
1. If RAM bit location 30H.2 is set to “0”, the following instruction sequence will execute the RET
instruction:
BTST
30H.2
; If 30H.2 = "1", then skip
RET
; If 30H.2 = "0", return
JP
LABEL2
Summary of Contents for KS57C2308
Page 30: ...ADDRESS SPACES KS57C2308 P2308 C2316 P2316 2 22 NOTES ...
Page 168: ...SAM47 INSTRUCTION SET KS57C2308 P2308 C2316 P2316 5 94 NOTES ...
Page 170: ......
Page 206: ...POWER DOWN KS57C2308 P2308 C2316 P2316 8 8 NOTES ...
Page 210: ...RESET KS57C2308 P2308 C2316 P2316 9 4 NOTES ...
Page 222: ...I O PORTS KS57C2308 P2308 C2316 P2316 10 12 NOTES ...
Page 272: ...LCD CONTROLLER DRIVER KS57C2308 P2308 C2316 P2316 12 24 NOTES ...
Page 280: ...SERIAL I O INTERFACE KS57C2308 P2308 C2316 P2316 13 8 NOTES ...
Page 294: ...MECHANICAL DATA KS57C2308 P2308 C2316 P2316 15 2 NOTES ...
Page 310: ...KS57P2308 P2316 OTP KS57C2308 P2308 C2316 P2316 16 16 NOTES ...
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