The 218x has a mode (M_MODE, if recall well) on which
the DSP makes the shift itself, but it only works for
1.15 x 1.15 = 2.30 -> 1.31.
For other formats, you'd heve to do the shift by
yourself, using the barrel shifter. What result do you
expect (expressed in your 2.14 format?)
--- Sonali Agarwal <> wrote:
> I have some confusion regarding the
> multiplication in ADSP 218x.
> For example, i want to multiply 1.5 * 1.5 which
> give 2.25 in assembly language of ADSP 218x.
> to represent 1.5 , i use the 2.14 format which gives
> it to be 0x6000.
> Now when i keep MX0 = 0x6000 and MY0 = 0x6000 and
> MR = MX0 * MY0, the result is
> MR2 = 00
> MR1 = 4800
> MR0 = 0000
> Now the problem is how to shift the data to bring it
> to the format understandable by the DSP.
> Can anybody help me in this regard. I hope i am able
> to make my point clear. Or if you can suggest soem
> technical material for this.
Jaime Andr Aranguren Cardona