Fast & Large block data transfer over USB - DE1/DE2 ?

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I tried both the latest version of VMWare (workstation 7.1) and VirtualBox, and neither could capture the USB-Blaster to sniff from Linux in a VM. I installed Ubuntu 11.04 (Wubi - binary blob on the windows partition), and it works great.

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I stopped to update my copy of Cygwin, and so a web search, but could not see a version of Wireshark I could just try under Cygwin.

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Apart from being able to access the USB Blaster through ftd2xx.dll, how do you want connect to the FPGA on the DE1/DE2 side?

Did you notice, that DE1 and DE2 implement a second set of software JTAG lines between the embedded USB-Blaster CPLD and the FPGA? The interface is used in the DEx_USB_API demonstration for data transfer from and to the Control Panel application.

Alternatively, you have communication options based on the VJTAG channel, e.g. the JTAG UART.

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This is where I am fairly ignorant - I have as yet never made use of JTAG or VJTAG ....

I have been using an "8-bit port into block of registers" with a simple 4-byte address and read/write data protocol, via the FTDI chips, partly inherited from an early set of fpga modules, and partly extended by myself .... been using it for a number of years, for a range of fpga projects.

I am trying to port this to the Morphic II - frustratingly is seems to sometimes work but mostly not, so I expect the state machine breaks when run faster. If we can build a bi-directional byte-stream vie the usb blaster to the FPGA, this could work on the DE1 as well ? This would be the first part of the project. The second would be to write a "block" transfer mode, to read the contents of a large block of memory.

At this point I really need advice on how to build a 4 byte-stream interface from the PC to the DE1, ideally as fast as possible. Then I can immediately run quite a bit of code.

Writing is : Write 4 bytes

Reading is : Write 3 bytes (or 4), Read 1 byte.

Not very efficient, but very flexible.

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You could try using the JTAG Avalon Master component and driving it from SystemConsole.

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Thanks - I am chasing up on JTAG, and on Avalon (which I have used).

The computer end I want to be my own programs (written in Apl).

AplX from MicroApl talks to the FTDI DLL fine, I use it to control my NMR spectrometer, which has a number of FTDI interfaced fpgas built into it now. It was AplX I used for those quick tests on the USB Blaster, a few pages ago.

I'm writing some detailed documents along with example code for;

* custom VJTAG components

* FTDI FIFO-to-Avalon-MM bridges

* customized use of the USB-Blaster, eg. for VJTAG communications

Be patient, and I'll post links soon. At the moment I'm writing TimeQuest analysis scripts for the designs.

Cheers,

Dave

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I'm writing some detailed documents along with example code for;

* custom VJTAG components

* FTDI FIFO-to-Avalon-MM bridges

* customized use of the USB-Blaster, eg. for VJTAG communications

Be patient, and I'll post links soon. At the moment I'm writing TimeQuest analysis scripts for the designs.

Cheers,

Dave

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WoW ! Thanks !

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Great. I haven't tried accessing a USB-Blaster under windows.

Write some test code;

a) Toggle TCK, while keeping all other bits high, so according to the protocol:

0011_1111 b /* bit mode, don't read-back, OE + TDI + CS# + CE# + TCK high */

0011_1110 b /* drop TCK low */

So fill a write buffer with 3-bytes, i.e., 3Fh, 3Eh, 3Fh, and write it to the USB-Blaster.

Probe the TCK pin and you will see a ~1us low pulse on TCK.

Viola, you now have control of your USB-Blaster!

Cheers,

Dave

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Well yes and no .....

I have for a USB Blaster JTAG connector connected to the JTAG connectore on Morphic II,

being the easiest for me to test :

Orientation : Pins 2, 10 : Gnd

Pin 4 : Vcc

Then the JTAG connectors are bought out to Morhic IO connectors :

Morphic II 0.1" connectors Altera USB Blaster (JTAG Mode)

J3-23 JTAG_TDI JTAG Interface Pin 9

J3-24 JTAG_TMS JTAG Interface Pin 5

J4-23 JTAG_TDO JTAG Interface Pin 3

J4-24 JTAG_TCK JTAG Interface Pin 1

If Toggle Toggling

Bit 0 TDI Pin 9, TMS Pin 5

If I write the 3Fh, 3Eh, 3Fh to the USB Blaster (and then call a Tx purge)

Or as decimal and binary :

63 62 63

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

Then I have toggling : TDI Pin 9, TMS Pin 5,

with TCK and TDO low.

This is indeed a 1us low pulse.

In fact it does not seem to matter which bit I toggle (other than the far left one),

I get the same behaviour.

Puzzled.

Perhaps you did not reset the JTAG TAP machine before starting your test.

Take a look at this test code.

Cheers,

Dave

Ah, thanks indeed, I will read it and try again tomorrow.

cheers,

Beau

Well I had a quick go ....

The reset string is :

jtag_reset

63 62 63 62 63 62 63 62 63 62 63 129 255

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

1 0 0 0 0 0 0 1

1 1 1 1 1 1 1 1

Yes ?

I really wonder if this is suffering from the same problem as I am having with the Morphic II driving software.

Lets see ...

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The reset string is :

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

0 0 1 1 1 1 1 0

0 0 1 1 1 1 1 1

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This is the bit-mode TAP reset sequence; it starts but putting all JTAG signals high, and then toggles TCK 5 times.

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1 0 0 0 0 0 0 1

1 1 1 1 1 1 1 1

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This is the 'alternative' method using byte-mode commands. The commands are; send a byte-mode command with 1-byte, followed by a byte of all 1's. This will toggle TCK 8 times. However, prior to this you need to set all the bits high, i.e., the correct sequence if using byte-mode is

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0 0 1 1 1 1 1 1

1 0 0 0 0 0 0 1

1 1 1 1 1 1 1 1

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Cheers,

Dave