how converter protocol pcm to spi

[Altera_Forum]

hi  

I wonder how can I do the protocol conversion to pcm spi, and how  thank you

[Altera_Forum]

pcmcia? to spi would be a major undertaking, and that would be a very fast serial bit rate. Of course it all depends on how fast your incoming data rate is. You can always buffer bursty data if you have the RAM for it and if the average data rate doesn't exceed your exit port rate.

[Altera_Forum]

PCM, pulse code modulation and protocol spi; serial peripheral interface protocol and I want to link these two protocols and I do not know how  

thank you

[Altera_Forum]

Oh well if it's what the wikipedia page looks like then it's just a parallel to serial converter with a slight twist. You just need to package your pcm codes to serial data. Opencores.org has a few different implementations of spi if you don't want to write your own. SPI is a very simple protocol though and if you don't need a generic design for it; it's just a clock and master in/master out going to slave out/slave in . You can pick a transfer size like 1 byte or 2bytes, depending on what seems optimal for your data size. Also, Since it has clock you don't have to worry about all the encoding schemes, as long as your signal is on the order of hundreds of megahertz and you stick to timequest recommendations for source synchronous designs. Your board guy would have to make sure and do things like matching impedances and pcb trace lengths if you say go above 50MHz (using LVDS would certainly help as well) or have really long traces. DCD also has IP for sale and it's a pretty easy to use SPI solution if you have some extra $$

[Altera_Forum]

I guess, that you are referring to a digital audio PCM interface? If so, why don't you simply mention the involved chip and bit rate? 

 Usual audio chips PCM interface (I have been using Analog and TI up to now) is very similar to SPI, except for a slightly different frame sync signal. I don't understand, what you exactly mean with converting PCM to SPI respectively linking the two protocols.  A PCM interface is basically a shift register and some glue logic. It can be build in a few lines of HDL.

[Altera_Forum]

thank you for your response;  

in fact pcm: pulse code modulation protocol and SPI serial peripheral interface protocol, which are two different protocols and I want them to communicate ie link between these two protocols, as if to be another master and slave but I t have an idea about the specific general architecture is what you can help me.

[Altera_Forum]

Depends on what you try to achieve. In my view both protocols can be handled by a nearly identical receiver or transmitter design. If you want to connect a "PCM" device to an existing SPI host (microprocessor, not FPGA) some adaption may be necessary. You should tell, which are the data source and sink in your communication problem.

[Altera_Forum]

in fact, I want to send a data by pcm and this data must be read by SPI maintaining the format used on this site http://en.wikipedia.org/wiki/protocol_converter

[Altera_Forum]

First understand both protocols. Create statemachines that encode and decode the low-level protocol formats. Then another block to transfer data between these two statemachines. Try and separate the lower-level protocol encoding from the higher-level data transfer "API".