Maxim Integrated DS4830A Optical Microcontroller User Manual

Page 217

Advertising
background image

DS4830A User’s Guide

217

NEG

Negate Accumulator


Description:

Performs a negation (two’s complement) of the active accumulator and returns the result
back to the active accumulator.


Status Flags:

S, Z


Operation:

Acc

 ~Acc + 1


Encoding:

15

0

1000

1010

1001

1010


Example(s):

; Acc = FEEDh, S=1, Z=0

NEG

; Acc = 0113h, S=0, Z=0

OR src

Logical OR


Description:

Performs a logical-OR between the active accumulator (Acc or A[AP]) and the specified src
data. For the complete list of src specifiers, reference the MOVE instruction. Because the
source is limited to 8 bits, the PFX[n] register is used to supply the high-byte of data for
16 bit sources.


Status Flags:

S, Z


Operation:

Acc

 Acc OR src


Encoding:

15

0

f010

1010

ssss

ssss


Example(s):

; Acc = 2345h for each example

OR A[3]

; A[3]= 0F0Fh

 Acc = 2F4Fh

OR #1133h

; MOVE PFX[0], #11h (smart-prefixing)
; OR #33h

 Acc = 3377h


Special Notes:

The active accumulator (Acc) is not allowed as the src for this operation.

OR Acc.<b> Logical OR Carry Flag with Accumulator Bit


Description:

Performs a logical-OR between the Carry (C) status flag and a specified bit of the active
accumulator (Acc.<b>) and returns the result to the Carry.


Status Flags:

C


Operation:

C

 C OR Acc.<b>


Encoding:

15

0

1010

1010

bbbb

1010



Example(s):

; Acc = 2345h, C=0 at start

OR Acc.1

; Acc.1=0

 C=0

OR Acc.2

; Acc.2=1

 C=1

Advertising