KS57C2308/P2308/C2316/P2316SAM47 INSTRUCTION SET

BTSTZ — Bit Test and Skip on True; Clear Bit

BTSTZ

dst.b

 

 

 

 

 

 

 

 

Operation:

Operand

Operation Summary

Bytes

Cycles

 

 

 

 

 

 

mema.b

Test specified bit; skip and clear if memory bit is set

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 a "1", the instruction immediately following the BTSTZ instruction is skipped; otherwise the instruction following the BTSTZ is executed. The destination bit value is cleared.

Operand

 

 

 

Binary Code

 

 

 

Operation Notation

 

 

 

 

 

 

 

 

 

 

 

 

mema.b *

1

1

1

 

1

1

 

1

0

1

Skip if mema.b = 1 and clear

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

memb.@L

1

1

1

 

1

1

 

1

0

1

Skip if [memb.7–2 + L.3–2].

 

 

 

 

 

 

 

 

 

 

 

[L.1–0] = 1 and clear

 

 

 

 

 

 

 

 

 

 

 

 

 

0

1

0

 

0

a5

 

a4

a3

a2

 

 

 

 

 

 

 

 

 

 

 

 

 

@H+DA.b

1

1

1

 

1

1

 

1

0

1

Skip if [H + DA.3–0].b =1 and clear

 

 

 

 

 

 

 

 

 

 

 

 

 

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. Port pin P2.0 is toggled by checking the P2.0 value (level):

BTSTZ

P2.0

;

If P2.0 = "1", then P2.0

"0" and skip

BITS

P2.0

;

If P2.0 = "0", then P2.0

"1"

JP

LABEL3

 

 

 

2. For toggling port pins P2.2, P2.3 and P3.0–P3.3:

LD

L,#0AH

 

BP2 BTSTZ

P1.@L

; First, P1.@0AH = P2.2

 

 

; (111100B) + 10B.10B = 0F2H.2

BITS

P1,@L

 

INCS

L

 

JR

BP2

 

5-41

Page 115
Image 115
Samsung KS57C2308 manual Btstz Bit Test and Skip on True Clear Bit, BP2 Btstz