PicoBlaze uart tx example

peepo

can any kind person point me to or provide a very basic TX example using Xilinx IP UART?
ie TX for RPi not USB...

following these old instructions for Papilio :
http://www.gadgetfactory.net/2010/11/xilinx-vhdl-uart-example/
I downloaded PicoBlaze 8-bit Microcontroller
http://www.xilinx.com/products/intellectual-property/picoblaze.html

but did not find simple example

I have Hamsterworks M16 RTL uart working fine.

thanks

~:"

Hoping that might perhaps double baudrate?

did not find on Hamsterworks or elsewhere

mjones

HI @peepo

Are you looking for an HDL UART example of a soft processor picoblaze example?

peepo

quite possibly? the gadget factory link suggests:
"the free Xilinx VHDL UART example is optimized for Xilinx
hardware, it provides the smallest and fastest UART possible."
and links to the picoblaze microcontroller.

so I imagine I am looking for: a simple HDL UART TX example using a soft picoblaze microcontroller to output one/two byte of data to RPi RX pin.

thanks!

I have a real problem with syntax, and the Xilinx documentation is really engaging, long and complex....
I would hope an example or two might also offer a way in...

mjones

Here is the uart project that was linked on the gadget factory blog post:

http://forum.gadgetfactory.net/index.php?/topic/2128-xilinx-vhdl-uart-example/#entry14616

Did you go through his linked youtube vidoes?  Based upon the titles Jack walks you through how to stitch the picoblaze to the uart example?

We also have a simple picoblaze example for the logi board in the logi-project repo.

peepo

Mike,

thanks again for your patience,

yup I went all through the video and example, it seems well out of date and no longer applicable.**
being for the Spartan3 on Papilio.

But, I checked again with old version of PicoBlaze for Spartan3, I added the files as per video 1

bbfifo_16.vhd  hard to read
kcuart_rx.vhd
kcuart_tx.vhd
uart_rx.vhd
uart_tx.vhd

update the .ucf for LogiPi but there are still a host of build errors,
as these are with Xilinx files eg kcuart_tx.vhd etc. it did not seem advisable to edit further.

I had also tried the current PicoBlaze download for Spartan 6
ISE has had a major upgrade, as has PicoBlaze and the files and folders indicated in the video are no longer available.
see 1:54 into video 1, there is currently no VHDL folder in the download from Xilinx given,
I hunted through folders, and tried various files, however these were not suitable for use in the example provided.

I did find

/UART_and_PicoTerm/uart_rx6.vhd
/UART_and_PicoTerm/uart_tx6.vhd

but not the others.

~:"

**that is unless I missed something obvious?

mjones

Hi @peepo

Sorry I overlooked that the project was spartan3 specific. The example he was using utilizes all of the spartan3 primitives and thus cannot be built on the spartan 6.   

There is a spartan6 version of the picoblaze/uart example project available with the picoblaze for spartan6 - "UART_and_PicoTerm".  There is a PDF guide in the "UART_and_PicoTerm" directory that walks through building the project on the spartan6.  

http://www.xilinx.com/ipcenter/processor_central/picoblaze/member/

I have not built the uart example, but put together a working picoblaze project in the logi-projects repo that you can use for reference relative to properly setting up the HDL for the spartan6.  The steps are also pretty well walked through in the user_examples and guides that are downloaded within the picoblaze for spartan 6 package.  See the attached screenshots for downloading the spartan6 version and getting to the uart example that is available in the package.

For reference - a working picoblaze project for the LOGI board:

https://github.com/fpga-logi/logi-projects/tree/master/picoblaze_s6_basic

As you mention the structure of the project may not be the same as the one generated by gadget factory based upon newer revisions and code changes.  It may be best to start by going through the "UART6_User_Guide_and_Reference_Designs_pdf" which is in th "UART_and_PicoTerm.pdf" document in the UART directory?

Cheers.

peepo

I'll give it a go, and comment later, thanks! ~:"