code for ramp generation in vhdl

[vishnu shankar]

hi i m new in fpga and vhdl programming. if any body have code for ramp generation in vhdl please pest it.and also suggest that how to define fpga pin to send this program in spi unit in fpga board for converting digital input to ramp output.

 

[elockpicker]

Hi,
If you are using ISE then to define pins you have to add a Constraint file to your project and set the pins according to your boards data sheet.
There are tutorials on this topic ,specially if you're using Xess's borads.

I don't know what the SPI expects but if you want to create a ramp you can simply use a For loop and increment the value of a bit vector and finally set it to zero .
You have to give this vector to a Digital-Analog-Converter.

 

[vishnu shankar]

actually we can't directely assign the dac pin in fpga. initially we have to interconnect it to spi interface then we'll give our output to the spi inputs but i m getting some problem in it.
spi interface have 5 pins p8, N8 ,u16,N10,T4, but i hv unable to proper initialisation of these pins if u have any idia about it please msg me.