How to set the datatype of outport of an S function to Fixed point datatype force fully ?

I am doing some S function releatd things. I need to set my s function output port datatype as a fixed point datatype with some resolution and offset.

Using function "mdlSetDefaultPortDataTypes" I am able to set the output port datatype as direct datatype only(like SS_UINT8). But not able to set some fixed point datatype.

Please suggest How to do that?

Thanks in Advance Rahul VP

Answer 1

[Kaustubha Govind]

1. Include fixedpoint.h and fixedpoint.c as described here.
2. Use ssRegisterDataTypeFxpBinaryPoint to register the desired fixed-point datatype and get its datatype ID.
3. Set the output datatype by passing the Datatype ID returned in (2) to ssSetOutputPortDataType.

See Writing Fixed-Point S-Functions for a complete reference.

[NithinRaj]

Hi,

If we use function like "ssGetDataTypeFracSlope" releated to fixedpoint then while mexing the s function c file, then you need to Pass an extra argument, -lfixedpoint, to the mex command. For example,

mex('sfun_user_fxp_asr.c','-lfixedpoint')

[Rahul Padmanabhan]

Thanks Kaustuba and Nithin...