sigmoid function for neuron implementation...

[rakesh_vnit]

hey everyone...
i am doin a mini project of fpga implementation of a neuron( neural networks).

here is the design for it...it contains an 8 bit multiplier. the output in accumulated with products of the next inputs multiplication outputs. now that i am multiplying 8 x 8 i am gettin 16bit output. to this i am addin a 20 bit offset. Now, here is the problem. the output from here should be converted back into an 8 bit number so that it can be the input for the next neuron. so, to make this 20 bit to 8 bit the sigmiod function is tobe used. the function is as shown in the picture below....

so can anybody help me with implementation of this functions?
plz post as soon as u can...its a bit urgent...thank u..

rakesh

 

[rakesh_vnit]

i was able to finish it wid out the help from here..hehehe.
anyways, for those who again want to do the same here is the help...