What do I need before design custom board? I'm a software guy

Why do you want to design your own board? There are plenty of development kits that you could use.

If you want to design the board so that you understand how its done, then you need to study other designs, eg., the designs of the development kits. Part of that study will be "why did they do that?".

Board design is not a simple matter of putting an FPGA on a PCB. You have to "design" the power supplies to meet the power-on sequencing requirements of the FPGA, you need to decide on and implement a power-on configuration method, you need to include JTAG, and connector interfaces to the outside world. Those connectors need ESD protection, possibly level translation, or voltage protection, etc.

There are plenty of experienced designers on this forum. If you describe why you want to do this, you'll get advice.

Cheers,

Dave

Thanks Dave,

I have completed my design on demo board. Now, I really want to custom FPGA board that needs to connect to other devices. Here is my thought.

- fpga, cyclone II

- voltage, 3.3v

- jtag

- gpio

- spi, i2c, rs232

What is ESD?

Best,

Sean

Hi Sean,

--- Quote Start ---

I have completed my design on demo board. Now, I really want to custom FPGA board that needs to connect to other devices. Here is my thought.

- fpga, cyclone II

- voltage, 3.3v

- jtag

- gpio

- spi, i2c, rs232

--- Quote End ---

Which demo board are you using?

So what is wrong with the demo board you have?

There's two ways you could design a custom board;

1. Build a custom interface board, eg., an HSMC daughter card, or something with a header or cable to your FPGA board.

2. Build a complete custom board that includes the FPGA.

--- Quote Start ---

What is ESD?

--- Quote End ---

Its the zapping sound you hear when you walk across the carpet and reach for your FPGA board ... and then it stops working :)

ESD = Electro-static Discharge

Cheers,

Dave

Thanks Dave,

I have Terasic Cyclone II FPGA Start Board. I have to build complete board that includes the FPGA. If this FPGA custom board works, I just replace the FPGA on real system.

I couldn't find document of pin layout. I look at Pin Planner in Quartus II, but I don't see how the USB JTAG connect to FPGA. Is that go through GPIO or special wires?

Best,

Sean

--- Quote Start ---

I have Terasic Cyclone II FPGA Start Board.

--- Quote End ---

Ok.

http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=53&no=83

--- Quote Start ---

I have to build complete board that includes the FPGA. If this FPGA custom board works, I just replace the FPGA on real system.

--- Quote End ---

The comment "I just replace the FPGA on real system" makes no sense. You cannot "just replace" an FPGA. BGA devices require special rework machines. What is it you are really trying to say?

Please explain your application and why the Terasic board does not meet your needs.

--- Quote Start ---

I couldn't find document of pin layout. I look at Pin Planner in Quartus II, but I don't see how the USB JTAG connect to FPGA. Is that go through GPIO or special wires?

--- Quote End ---

These are basic questions that have multiple answers; the Altera web site has the pin assignments for each FPGA in a particular package, the DE1 schematic will show you the pin assignments of this specific board, and the pin planner should have those pins shown on the graphic of the device.

My impression is that designing an FPGA board from scratch will be challenging for you. I would recommend considering designing an interface board that plugs into your DE1 board.

Cheers,

Dave

Dave,

Ok. I have a schematic that has USB Blaster pins, to EPCS4N EEPROM and to FPGA design board. But now, my manager wants to use Non-volatile memory to get cheaper (I guess). Does Altera have that non-volatile memory to replace EEPROM.

Thanks,

Sean

Hi Sean,

--- Quote Start ---

Ok. I have a schematic that has USB Blaster pins, to EPCS4N EEPROM and to FPGA design board. But now, my manager wants to use Non-volatile memory to get cheaper (I guess). Does Altera have that non-volatile memory to replace EEPROM.

--- Quote End ---

The EPCS4 is SPI Flash (not EEPROM). The "Altera" part is a rebranded SPI Flash with ID that matches parts from Micron (Numonyx). Search the group for SPI flash and you'll get examples of part numbers.

If you want the ultimate in cheap, you could just force your end-user to configure the FPGA via JTAG each time they use it. Though even in that case I would recommend including the PCB footprint for the EPCS flash regardless of whether you load it or not.

You can also just interface the FPGA to a USB-to-FIFO chip from FTDI and bit-bang the device to configure it. FTDI's Morphic-II module has details on what you can do.

Cheers,

Dave

Hello Dave,

We really don't want end-user to configure through JTAG. We just want to program once at factory only. Is there a non-volatile memory to configure FPGA when turn on?

Best,

Sean

Hey Sean,

--- Quote Start ---

We really don't want end-user to configure through JTAG. We just want to program once at factory only. Is there a non-volatile memory to configure FPGA when turn on?

--- Quote End ---

You really need to *read* the FPGA documentation - even software guys need to read :)

The non-volatile memory is the EPCS device. As I commented, this is re-branded SPI flash, which can be replaced by several lower-cost devices (specific part numbers can be found in other threads).

Cheers,

Dave

Thanks Dave,

I will look at digikey for Part Number.

Thank again for your help.

Sean