User`s guide

Inline Assembly Language and Intrinsics
Intrinsic Functions
162
Targeting MC56F83xx/DSP5685x Controllers
L_msu
Multiply two 16-bit fractional values and subtract this product from a 32-bit fractional
value, saturating if necessary. Generates a 32-bit result.
Assumptions
OMR’s SA bit was set to 1 at least 3 cycles before this code, that is, saturation on data
ALU results enabled.
Prototype
Word32 L_msu(Word32 laccum, Word16 sinp1, Word16 sinp2)
Example
short s1 = 0xC000;/* - 0.5 */
short s2 = 0xC000;/* - 0.5 */
long result, Acc = 0;
result = L_msu(Acc,s1,s2);
// Expected value of result: 0.25
L_mult
Multiply two 16-bit fractional values generating a signed 32-bit fractional result.
Saturates only for the case of 0x8000 x 0x8000.
Assumptions
OMR’s SA bit was set to 1 at least 3 cycles before this code, that is, saturation on data
ALU results enabled.
Prototype
Word32 L_mult(Word16 sinp1, Word16 sinp2)