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Home » RBC Forums » General Discussion » "The Thing": a new Multicomp FPGA board... ((STM32F103C8T6 + EP2C5T144C8N + AS6C4008))
"The Thing": a new Multicomp FPGA board... [message #3726] Sun, 12 November 2017 06:13 Go to next message
just4fun is currently offline  just4fun
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Hi all,
I'm just starting now to design an Open Source FPGA board (Cyclone II based) and I'd like to make it "compatible" with the Multicomp project.

I'm now in the early stage of "info gathering", and I'm reading the documentation on the Grant's site and here, and starting to analyze the Quartus II projects.

The board that I've in mind is a beginners low cost FPGA dev board (probably with a M3 Cortex "support" MCU as I did for a previous CPLD dev board), and with some "stuff" like leds, keys, and a 7-segment 4 digits display. I'd like to make this board "compatible" with the Multicomp, adding the SRAM, SD socket, VGA output, etc.

I'm trying to maintain the original FPGA pin assignment, but I've noticed that the DEV_CLRn (FPGA pin 142) is used, and this is "annoying" for me because I want connect it to a key (to clear all the internal FFs), and the same with DEV_OE (to a switch, but this one is not used in the Multicomp).

More, changing others FPGA pins assignments can be handy in the PCB layout phase.

Of course this will require to change the "swapped" pins assignments accordingly in the Quartus II project, but this is not a big problem.

I'm just wondering if "swapping" some FPGA physical pins can cause any FPGA problem with the Multicomp... Rolling Eyes (may be I'm over estimating this thing)

Any advice...?

Cheers

[Updated on: Thu, 31 January 2019 08:42]

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Re: Starting a new Multicomp FPGA board: a question about FPGA pin assignments [message #3740 is a reply to message #3726] Mon, 13 November 2017 23:24 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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Auto-answer after some thoughts... No, there shouldn't be any problem (or something I could not fix afterwards). Now starts the fun... (or the hell) Laughing
Re: Starting a new Multicomp FPGA board: a question about FPGA pin assignments [message #3794 is a reply to message #3740] Mon, 20 November 2017 02:11 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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UPDATE: the DEV_OE pin (FPGA pin 40) is used in the Multicomp Board v1.10 as an external RTC pin, so I must remap it too to free the DEV_OE function (RTC not used in the Z80 "cycloneiic-z80" VHDL)...
Re: Starting a new Multicomp FPGA board... [message #5423 is a reply to message #3794] Fri, 02 November 2018 08:07 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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I've decided to "resume" this thing just now, having paused it for "some" months to do other boards (my free time is very limited, so I can't play with more than one "project" at a time...).

The schematic was already done (may be some changes at the end), so the next step is the PCB layout.

I've also "switched" at Kicad 5 now, so this one will be the first try with it. The schematic import from Kicad 4 was easy, and I've just finished to add the needed footprints (probably I will change somethings in some footprints, but not for now).

An interesting thing I've noticed is that now the PCB editor "sorts" the footprints probably using an "adjacency" criteria when importing a netlist the first time:

index.php?t=getfile&id=1105&private=0

Now it's time to do "some" routing... fingers crossed...
Re: Starting a new Multicomp FPGA board... [message #5429 is a reply to message #5423] Sun, 04 November 2018 07:15 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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Rainy days... so I've started to place the components.
The new Kicad 5 PCB editor allows more faster operations in the "Modern toolset" mode, but it seems that some edits require to switch to the "Legacy toolset", e.g. to drag a footprint.

I've started with the power supply and the STM32 "stimulus generator" MCU (as I did in this CPLD dev board), just to have an idea before to start to place tracks...

index.php?t=getfile&id=1106&private=0

I'm very curious to see how it will go...
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Re: Starting a new Multicomp FPGA board... [message #5455 is a reply to message #5429] Sat, 10 November 2018 07:58 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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After 3 attempts may be I've found a decent placement for the bigger parts... (I mean... without a 100% impossible to route ratsnest...)

Now I need to do some FPGA pins "remapping" for a better routing (to have a chance...). The hardest part is yet to come...

index.php?t=getfile&id=1110&private=0

index.php?t=getfile&id=1109&private=0

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Re: Starting a new Multicomp FPGA board... [message #5458 is a reply to message #5455] Sat, 10 November 2018 12:26 Go to previous messageGo to next message
rhkoolstar is currently offline  rhkoolstar
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To save space you could use a micro-SD card socket. The standard size is getting rarer and more expensive anyway.

Using smt pushbuttons saves real estate on the backside.

Rienk
Re: Starting a new Multicomp FPGA board... [message #5480 is a reply to message #5458] Mon, 12 November 2018 04:32 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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rhkoolstar wrote on Sat, 10 November 2018 12:26
To save space...
Rienk


Currently I have only a lot of standard sockets, but an other lot of micro-SD sockets is on the way. I prefer to have the sockets on my table before check the footprint...

Just ordered a lot of smt buttons (same dimensions but smt)... just in case... Laughing

Thanks for the suggestion...

Re: Starting a new Multicomp FPGA board... [message #5489 is a reply to message #5480] Mon, 12 November 2018 15:15 Go to previous messageGo to next message
rhkoolstar is currently offline  rhkoolstar
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here is my TF-card footprint, maybe that fits with yours...
Re: Starting a new Multicomp FPGA board... [message #5495 is a reply to message #5489] Tue, 13 November 2018 10:21 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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Thanks! I'll check it when the small sockets arrive...
Re: Starting a new Multicomp FPGA board... [message #5540 is a reply to message #5455] Fri, 16 November 2018 04:38 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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I've done some progress and I'm starting to feel "optimistic"... so I've found a name for it... "The Thing" Laughing

index.php?t=getfile&id=1142&private=0
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Re: Starting a new Multicomp FPGA board... [message #5605 is a reply to message #5540] Sat, 24 November 2018 08:34 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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Now only a few tracks left...

As for the SD, I want to try to place both footprints, so it should be possible to choose the micro-SD or the full size socket.

index.php?t=getfile&id=1151&private=0

index.php?t=getfile&id=1153&private=0
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[Updated on: Sat, 24 November 2018 09:00]

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Re: Starting a new Multicomp FPGA board... [message #5634 is a reply to message #5605] Wed, 28 November 2018 23:26 Go to previous messageGo to next message
jonb is currently offline  jonb
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Couldn't you fit a micro SD card socket footprint inside the full sized footprint? Then you could choose what to fit when building it.

I recently bought a full sized socket for a Cyclone II-C board. Cost me £6 which I think was pretty eye watering. Even more annoying, after ordering I found one of those little carrier boards with a socket on it in one of my parts bins so ended up desoldering the socket and using it instead.
Re: Starting a new Multicomp FPGA board... [message #5635 is a reply to message #5634] Thu, 29 November 2018 01:34 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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jonb wrote on Wed, 28 November 2018 23:26
Couldn't you fit a micro SD card socket footprint inside the full sized footprint? Then you could choose what to fit when building it.


Already done... Smile

index.php?t=getfile&id=1156&private=0

index.php?t=getfile&id=1157&private=0
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Re: Starting a new Multicomp FPGA board... [message #5675 is a reply to message #5635] Sun, 02 December 2018 08:02 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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I've realized that my miscroSd socket (still on the way...) has a completely different footprint (it seems very common on ebay). Searching around I've found a possible good one (here) and the right datasheet (both attached):

https://kicad-info.s3-us-west-2.amazonaws.com/original/2X/8/8d1dbfabaa90b65dad4965a185d7e55230d35003.png

I've also added some Test Points that should work with these (Never used up to now. I've just ordered a lot):

https://ae01.alicdn.com/kf/HTB18.bRpr5YBuNjSspoq6zeNFXaE.jpg

So this is the situation now after some minor changes:

index.php?t=getfile&id=1167&private=0

index.php?t=getfile&id=1168&private=0

Now I have to do some more checking, but the layout should be finished...
Re: Starting a new Multicomp FPGA board... [message #5807 is a reply to message #5675] Thu, 27 December 2018 05:44 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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PCBs are just arrived. Now it's time to make some "magic smoke"... Very Happy

index.php?t=getfile&id=1209&private=0
Re: Starting a new Multicomp FPGA board... [message #5831 is a reply to message #5807] Tue, 15 January 2019 01:50 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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Tested the JTAG and ASP programming mode and both worked!
I've also tested the SFL IP core (used as a bridge to interface between JTAG and Active Serial Memory Interface in the FPGA itself) to program the eeprom using the JTAG connector.

Now I can go head to complete the assembling...

https://farm8.staticflickr.com/7881/46692169182_67f21c2f6a_c.jpg
Re: Starting a new Multicomp FPGA board... [message #5837 is a reply to message #5831] Thu, 17 January 2019 12:05 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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I've assembled some more stuff to test the first Multicomp, a 6809 CPU with Basic ROM, 2KB internal RAM, VDU and a PS/2 keyboard:

https://farm8.staticflickr.com/7878/32904025618_3f1776c78e_b.jpg

and this was the result...

https://farm5.staticflickr.com/4841/32904026118_f9e60b266f_c.jpg

It works!!! Laughing

Now the next step will be test the SD and the external 512KB SRAM...
Re: Starting a new Multicomp FPGA board... [message #5901 is a reply to message #5837] Thu, 31 January 2019 08:49 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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Tested a Multicomp Z80 with 64KB RAM (ext), 16 HDs on SD, VDU, PS/2 Keyb., CP/M 2.2 as running OS:

https://farm8.staticflickr.com/7903/39974592433_73ef791f34.jpg

https://farm5.staticflickr.com/4862/39974591963_7e6428821c.jpg

https://farm8.staticflickr.com/7827/46025165705_44c111ef69.jpg

Next step will be test an other PCB using a micro SD socket instead.
Re: Starting a new Multicomp FPGA board... [message #5934 is a reply to message #5901] Wed, 06 February 2019 09:34 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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A short video of the Z80 multicomp in action...: https://www.youtube.com/watch?v=j8qfqlEfJm8
Re: "The Thing": a new Multicomp FPGA board... [message #5995 is a reply to message #3726] Fri, 22 February 2019 07:52 Go to previous messageGo to next message
just4fun is currently offline  just4fun
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I've just tested another board with a micro-SD socket:

/forum/index.php?t=getfile&id=1266&private=0
/forum/index.php?t=getfile&id=1267&private=0

Next days I'll start to publish all the details (schematic, gerber files, BOM, etc...) here.

Re: "The Thing": a new Multicomp FPGA board... [message #6064 is a reply to message #5995] Sat, 09 March 2019 01:58 Go to previous message
just4fun is currently offline  just4fun
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Playing with the 7-segment display (video): https://youtu.be/WFvbjn-bLU4

More info here.
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