What MCU will be needed?

[sskillz]

Hello,
I have to analyze a stream of data coming down a single line, that signal is NRZI encoded and the data itself is encoded from 8bits to 16bits code words so that there will be less trailing '1' and '0'.
For example '01110000' becomes the code word of '0100100001000001". This is done by a conversion table. To add to this, every x of data a 4sync bytes (32bit) are sent. So its something like this:
CodeWord0 CodeWord1 CodeWord2 CodeWord3.... CodeWord99 SyncByte CodeWord100
Codewords represent a 16bit of data, and Syncbyte 32bit of sync data.
The speed of the data (after decoding) coming down the line is about 15MBs, meaning that the frequency of the line
is about 240Mhz (16bits * 15Mega) . This is really fast and analyizing this only in MCU will require atleast 240MIPS. So my plan is using a a shift register of 16bits to parallel
read 16 bits at a time(using 16 inputs) at a frequency of just 15Mhz. I can read a codeword at a time or half a syncat a time.

Now I need to write the decoded data to a storage device, like a SDHC Card.
What minimum MCU will be able to handle all this?

Thanks ahead.

 

[sskillz]

Its its not the right forum, can someone move it please?

 

[alexxx]

What minimum MCU will be able to handle all this?

I am confused with the provided information. So you have data with 15MBs rate. What protocol are you using? Where those data are coming from? Why do you need a serial to parallel converter? Can't you just read them serially? What is the part number of the shift register you are referring to? Is there any schematic available? What other tasks are involved in this project? Are you already using an MCU that is considered to be improper for this application and why?

Its its not the right forum, can someone move it please?

Such a thread will not attract many answers. You have to be a mind teller or mentalist to give an answer on such a general description. You created a big post with useless and questionable information (like incoming words coding or the attempt to convert Mbps to MHz). Please provide all the technical information in details, and then someone who has experience on this, will propably answer.


Alexandros

 

[keith1200rs]

Can an SDHC card take data at that rate? I have done high speed serial links at 280Mbps many years ago but used Gennum serialiser/dederialiser chips to do the encode/decode and a CPLD to handle the data at each end. Admittedly microcontrollers weren't as fast 10 years ago, but I would still probably take the same approach now.

Keith

 

[sskillz]

Thanks for the replies,
I'm not using any current MCU, I just wanted a estimate on which one will do.
Using a serial port will require a high serial clock no? Since its tied to the chips clock that will make the MCU much more expensive.
It hard to find a shift register that works with a clock rate of ~250MHZ (100341 works on 400MHZ but its discontinued), so I could built one using fast flip flops.
SDHC x133 and above should handle 20MBs.

I tried writing this question using what it really is but no one answered so I wrote it a more general way.
Anyway, The data comes from a optical reader of a DVD Rom which reads at 12X Speed (15MBs)
My plan is not to control the DVD drive just splice into the optical reader lines and sniff the data sectors and store them.
The protocol is how standard DVD rom works - Standard ECMA-267 (Read here).
I couldn't find any hardware designs of DVD-Drives (Or cd-roms for that matter) or any relating projects, if you can help me find some, that will be great.

 

[keith1200rs]

I would suggest you look at products from companies like Gennum who make high speed serialiser-deserialiser chips which do the hard bit for you. Then use a CPLD for handling the data - it is far more suited to it than a micro.

Keith.

 

[sskillz]

I never tried CPLD or FPGA, cause I don't know how to design them. If it wasn't a completely different
approach to the solution I would have tried learning them.
A lot of DVD Drives uses singlechip microcontrollers I just don't know how powerful they are.
I have experience with 8051 but most are not powerful enough and I think this is a good project to start learning ARM and using something like 50MHZ LPC1114 Cortex-M0 (This board for example: Click Here)
I just want to know if it should be enough.

On a second note I could use the CPLD for the first decoding and deserializing of the information.