[sdiy] Avnet Spartan-3A Dev Board - USB-UART Bridge Info

[Scott Gravenhorst]

One more thing I should mention - the PSoC only translates from USB to a serial line
connected to the FPGA, there may be a UART internal to the PSoC to do this, but you still
need to put a UART in the FPGA design to interface with the Tx and Rx pins coming from
the PSoC.

Sorry this is a tad off topic since this specific project is not SDIY, but I think this
USB-UART bridge can be a good thing for synth projects done on the board.  I use a serial
connection from my workstation to the FPGA boards I work with (for synths) to send patch
data without having to deal with MIDI under Windows (I have _no_ clue how that is done).

Csaba Zvekan <czvekan at gmail.com> wrote:
>
>On Dec 18, 2008, at 3:09 PM, Scott Gravenhorst wrote:
>
>> Csaba Zvekan <czvekan at gmail.com> wrote:
>>> Thanks Scott for the info,
>>>
>>> Do you have some updated pages or notes we can print out . So we can
>>> attach it to the User guides pdf or something.
>>> I guess I could print out this mail , right :)  hmmm ok.
>>
>> That works.  I was frustrated waiting for the PIC board for my  
>> infrared project, so I
>> started developing on the Avnet board just to get it working.  I  
>> read through the docs
>> and it looked easy to get serial data in/out via USB through the  
>> UART bridge - but it
>> wouldn't work!  As you know, I'm making a single bit sampler and I  
>> needed to resample
>> all the buttons at a slower sample rate, but I needed to get the  
>> data into my
>> workstation.  Finally, I found some posts on the Avnet forum for the  
>> board and others
>> had discovered the reversed pins.  I discovered the bad pin labeling  
>> myself, ISE
>> complained about pin P22 not existing and refused to compile.  Then  
>> I went to the
>> schematic which showed A3 and B3 for the pins, but they were  
>> reversed.  I figured it
>> was another error in the docs, so I looked at the forum where I  
>> found out about the
>> reversed pins.  Once I fixed that, it worked like a champ, no setup  
>> or config, it seems
>> automagically capable of 115.2 Kbaud...
>All right , Scott . Let us/me know how you ported your project to the  
>PIC-board . And how it turned out . We hope you can record your  
>digitally broadcasted TV-series without any hassle pretty soon. :)
>I don't mean to bore anybody but I was pretty busy myself . I have  
>redrawn /designed Xilinx's Parallel Cable Programmer. This programmer   
>could be used for the AVNET Spartan 3A board with the 14 way 2.0mm  
>header. Leaving the USB and PSOC part for other use.
>Plus Windows XP users that upgraded to Service Pack 3 would not have  
>any trouble anymore. Since we don't use AVNET's programmer Software  
>instead Xilinx's IMPACT. :)
>Originally I intend to use this programmer for my home brew CPLD  
>development board (I'm still brewing). If anybody is interested in  
>what I just wrote contact me and /or I will send you the link to the  
>project.
>
>Csaba
>
>
>
>>
>>
>>>
>>> Csaba
>>>
>>>
>>> On Dec 18, 2008, at 1:45 AM, Scott Gravenhorst wrote:
>>>
>>>> music.maker at gte.net wrote:
>>>>> Anyone who has this board - a note about the USB-UART Bridge
>>>>> (which is useful for getting information to/from a PC), the pin
>>>>> information in the user guide PDF is wrong, there are no such
>>>>> pins on this particular FPGA. The schematic shows the correct
>>>>> pins, but because they are labeled from the PSoC perspective,
>>>>> they appear backwards from the FPGA perspective. I.e., the Rx pin
>>>>> is really the transmit data pin from the FPGA to the UART.
>>>>                                                     ^^^^ --- PSoC
>>>> not UART.
>>>>
>>>> Phhhht.
>>>>
>>>> -- ScottG
>>>> ________________________________________________________________________
>>>> -- Scott Gravenhorst
>>>> -- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/ 
>>>> FPGA_synth/
>>>> -- FatMan: home1.gte.net/res0658s/fatman/
>>>> -- NonFatMan: home1.gte.net/res0658s/electronics/
>>>> -- When the going gets tough, the tough use the command line.
>>>>
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>>>
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>>
>> -- ScottG
>> ________________________________________________________________________
>> -- Scott Gravenhorst
>> -- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/ 
>> FPGA_synth/
>> -- FatMan: home1.gte.net/res0658s/fatman/
>> -- NonFatMan: home1.gte.net/res0658s/electronics/
>> -- When the going gets tough, the tough use the command line.
>>
>
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-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.