Sonic Alert msm85c154hvs, msm83c154s, msm80154s user manual 280, RS1

Models: msm83c154s msm85c154hvs msm80154s

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MSM80C154S/83C154S/85C154HVS

30. DEC @Rr (Decrement indirect address)

 

 

 

7

 

 

 

 

 

 

 

 

0

 

Instruction code

:

 

0

0

0

1

0

1

1

 

r

Byte 1

Operation

: ((Rr))((Rr))–1

r=0 or 1

 

 

 

 

 

Number of bytes

: 1

 

 

 

 

 

 

 

 

 

 

 

Number of cycles

: 1

 

 

 

 

 

 

 

 

 

 

 

Flags

:

 

C

AC

F0

 

RS1

RS0

OV

F1

P

(PSW)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Description

 

 

 

 

 

 

 

 

 

 

: The contents of the data memory location addressed by the

 

 

register r contents are decremented by 1.

 

 

Example DEC @R0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

 

 

0

 

 

 

 

 

 

Instruction code

:

0

0

0 1

0 1

1 0

Byte 1

 

 

 

 

Before execution Register 0

0 1 1 0 1 0 1 0

70 6AH

1 0 0 1 0 0 0 0

70

After execution Register 0

0 1 1 0 1 0 1 0

70 6AH

1 0 0 0 1 1 1 1

70

280

Page 287
Image 287
Sonic Alert msm85c154hvs, msm83c154s, msm80154s user manual 280, RS1