Flexray WaveForm Comparison

In this i will post two waveforms. The top waveform is the simulated waveform from the RTL synthesis of VHDL code. The second waveform is the actual flexray static frame waveform. We can see that the two waveforms are identical .

Please click on the image for clear image.

The comparison between the simulated waveform and the example wave form shows that the designed system is working as expected.

FLEXRAY CODEC BLOCK

The "CODEC" block basically decodes or encodes the flexray frames. The encoder basically gets the raw frames from a user RAM or from a controller and then encodes the frame according to the flexray protocol.

So to begin with i will first build a flexray transmitter . This module is basically an encoder .The Flexray frame resides in a RAM. This unit copies the RAM content one by one and then simulatniously transmits each bit of the frame serially.It also appends 3 bits

1)TSS(Transmit Start Sequence)
2)FSS(Frame Start Sequence)
3)BSS-starting of every byte of frame(Byte Start Sequence)

The basic block diagram is shown below:-


The above block is realized in VHDL and its RTL synthesis is done in XILINX 8.1. The synthesis thus produced is verified by comparing the simulation result to an example flexray waveform.