Encoding:

P32A

001000

rt

rs

rd

x

1111000

101

6

5

5

5

1

7

3

Format: 

ADDWC rd, rs, rt

DSP

Add Word with Carry Bit

Purpose:

Add Word with Carry Bit

Add two signed 32-bit values with the carry bit in the DSPControl register.

Description: 

rd = rs + rt + DSPControlc:13

The 32-bit value in register rt is added to the 32-bit value in register rs and the carry bit in the DSPControl register.

The result is then written to destination register rd.

If the addition results in either overflow or underflow, this instruction writes a 1 to bi t 20 in the ouflag field of the

DSPControl register.

Restrictions:

No data-dependent exceptions are possible.

Operation: 

ValidateAccessToDSPResources()
temp32..0 = ( GPR[rs]31 || GPR[rs]31..0 ) + ( GPR[rt]31 || GPR[rt]31..0 ) + ( 032 || 
DSPControlc:13 )
if ( temp32 != temp31 ) then
   DSPControlouflag:20 = 1
endif
GPR[rd]31..0 = temp31..0

Exceptions:

Reserved Instruction, DSP Disabled