Schematic diagram missing one page, 6-pin JTAG header and IC 6 are not installed on actual board

[YangQi]

Hi: 

I am learning to use the Basys 3 for my project. However, when I went over the Reference Manual and the schematic diagram. I have some problems, just want to be clear before I get in that to have a better understanding of how Basys 3  works in different parts.

First, on the schematic diagram, IC6, which is a different package type of IC8, is labeled "No load", and on my actual board I can only find IC8, which is the S25FL032P0XNFI00 with SOIC16 package. Does it mean that both IC6 and IC8 work in a same function here, but we may pick either of them. And the schematic diagram can also be simplified by directly getting rid of one of them that we didn't select to use. 

Secondly, The 6-pin header J5 is also labeled with "No Load", but it seems to be the JTAG port for programming when the jumper JP1 selects the JTAG option, and we can use some platforms such as the USB-to-JTAG cable produced by Xilinx to program the FPGA. If so, if I want to do programming in this way, how can I use JTAG headers to do programming on my board?

Moreover, the page 4 of schematic diagram is missing. And I noticed that, according to some issues of  proprietary, the FT2232 part is protected. However, I think there are 11 ICs on the basys 3 board. And I can't find any explanations about IC5 and IC3. What are those for? 

Thank you for reading this. I am really interested in getting started with FPGA by starting from basys 3. I would really appreciate your help.

[Commanderfranz]

Hi YangQi,

To program the Basys 3 via JTAG you don't need a JTAG programming cable as the programming circuitry is located on board, the missing portion of the schematic. 

The methods for programming the Basys 3 are described in the Basys 3 programming guide. 

For more help getting started there are lots of tutorials and a getting started guide on the resource center. 

 

[D@n]

YangQi,

Welcome to the Basys3 board!  That was the very first board I bought from Digilent and aside from the lack of useful memory to drive a video port, I've been very pleased with it.

I think you'll find a JTAG port located underneath the JA PMod interface on the bottom side of the board.  You'll need to do some soldering to connect to it.  However, what [@Commanderfranz] said was right: it's not a supported interface.  Further, the last time I thought I understood where a JTAG was that I might use, it was on the end of the CMod-S6.  I only later learned that that particular JTAG interface was used for an onboard PIC, and useless as an FPGA JTAG.  So, while I think there's a valid JTAG underneat the JA PMod connector, I haven't tested it, Digilent doesn't support it, and it might not even hook up to the FPGA in the end anyway.

As for IC8 and IC6, I also puzzled over that part of the schematic when I first got my board.  I think you have the proper understanding of it, though: one or the other chip can be placed on the board but not both.  If that's a chip you are interested in working with, you can find Verilog code that I put together some time ago for accessing the QSPI flash via a Wishbone bus. 

I also just took a long hard look at my Basys3 board.  I can't seem to find IC3 or IC5 on the board, so I don't know how to help you there either.  It may be that they are part of an off-board programming interface that is removed prior to shipment (??)  I don't know.

At any rate, good luck with your new board!

Dan

[YangQi]

6 minutes ago, D@n said:

YangQi,

Welcome to the Basys3 board!  That was the very first board I bought from Digilent and aside from the lack of useful memory to drive a video port, I've been very pleased with it.

I think you'll find a JTAG port located underneath the JA PMod interface on the bottom side of the board.  You'll need to do some soldering to connect to it.  However, what [@Commanderfranz] said was right: it's not a supported interface.  Further, the last time I thought I understood where a JTAG was that I might use, it was on the end of the CMod-S6.  I only later learned that that particular JTAG interface was used for an onboard PIC, and useless as an FPGA JTAG.  So, while I think there's a valid JTAG underneat the JA PMod connector, I haven't tested it, Digilent doesn't support it, and it might not even hook up to the FPGA in the end anyway.

As for IC8 and IC6, I also puzzled over that part of the schematic when I first got my board.  I think you have the proper understanding of it, though: one or the other chip can be placed on the board but not both.  If that's a chip you are interested in working with, you can find Verilog code that I put together some time ago for accessing the QSPI flash via a Wishbone bus. 

I also just took a long hard look at my Basys3 board.  I can't seem to find IC3 or IC5 on the board, so I don't know how to help you there either.  It may be that they are part of an off-board programming interface that is removed prior to shipment (??)  I don't know.

At any rate, good luck with your new board!

Dan

Dear Dan:

Thank you so much for replying! I really appreciate it. It makes a lot of sense to me! By the way, the IC3 and IC5 are on the back of my board, on the corner near by IC10. I think they might be some off-board programming hardware like you said. And for JTAG headers, I would like to try it to see if it would work or not. 

Thank you again for replying! It helped me a lot. And thank you for encouraging! 

Best regards,

Yang

[D@n]

Yang,

Okay, I see them now.  I have no idea what they do, although I would note their proximity to the PIC chip that runs the HID interface on the other side of the board.  Perhaps they are related?  I might've thought they were power chips, such as a voltage regulator, except IC10 and IC11 look like they supply all fo the necessary power rails.  So, bottom line again, I have no idea what they do.

Yours,

Dan