Rn = –Rx - Analog Devices ADSP-2106x SHARC User Manual

ALU Fixed-Point
B Compute Operations
Rn = –Rx
Syntax:
Rn = –Rx
Function:
Negates the fixed-point operand in Rx by twos complement. The result is
placed in the fixed-point field in register Rn. The floating-point extension
field in Rn is set to all 0s. Negation of the minimum negative number
(0x8000 0000) causes an overflow. In saturation mode (the ALU saturation
mode bit in MODE1 set), overflow causes the maximum positive number
(0x7FFF FFFF) to be returned.
Status flags:
AZ Is set if the fixed-point output is all 0s
AU Is cleared
AN Is set if the most significant output bit is 1
AV Is set if the XOR of the carries of the two most significant adder
stages is 1
AC Is set if the carry from the most significant adder stage is 1,
otherwise cleared
AS Is cleared
AI Is cleared
B – 14
www.BDTIC.com/ADI