FTDI where are you?

If you want to bitbang, the Vinculum might be a better choice. But it doesn't have the MPSSE machine.

If you want to use the FT2232 in 245 FIFO mode, you need the EEPROM and need to program it accordingly.

--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

Thanks Uwe,

I'm just wondering why you think the Vinculum would be a better choice for bitbanging, no where in the VNC1L datasheet does it even talk about bitbanging. ??

Thomas

^^^^^

Sorry, I thought about the EEPROM in the VINCULUM and the built in serial number, but didn't look specifically about bitbanging. But in the "Hardware Feature" entry in the datasheet, "Up to 28 GPIO" are mentioned. GPIO pins are normally what is used for bitbanging.

But thinking further, as there is no programming environment available for non-NDA users, probably the GPIO pins can't be made to bitbang for normal users neither...

--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

Go through an anonymous proxy. Here in South Africa the internet access is particularly bad and some web sites are basically impossible to connect to. (Incompitence more than malice from the telcos part). I have found that connecting through many of the available anonymous proxy servers allows me to connect to these "problem" sites.

Regards Anton Erasmus

Yes, unfortunately serial EEPROM and 3 x resistors. If you want 2 x serial no EEPROM required, I personally wished that two pins had been used for selecting each port as serial/parallel.

I'll add a note on my web page.

You may be at the limit of the device as these are 12Mbps (High speed NOT full speed) devices. So 12Mbps transfer rate is for BOTH ports combined.

It does not take much to build up a test device, crystal, few resistors, serial EEPROM and QFP package. I knocked up a test USB hub and FT2232D on a couple of Schmart boards. I could email a link to a photo if you want.

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Paul Carpenter          | paul@pcserviceselectronics.co.uk
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12M is full speed, 480M is high speed - 'full' referred to the maximum speed at the time of the 1.1 standard. Confusing I know!

VNC1L is a totally different beast - it's a host controller

Have you looked at the FT245R?

if you want really quick USB transfer, look at this :

expensive, but pretty flexible.

That is what I meant to put, you are right. I confusingly got them wrong way round.

If he needs a FIFO port and bit banging at same time FT2232D or other chip is better. Having done something similar hence my example page.

The thing you have to watch is how many USB 2.0 devices are actually USB 1.1 that works with USB 2.0.

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Paul Carpenter          | paul@pcserviceselectronics.co.uk
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I think that they should have just put the EEPROM right on the chip. Or even have volatile configuration registers on the chip that you can configure via their driver command set. It's expensive to inventory and control new components.

Thomas

On embedded world 2007 the people at the FTDI booth told my that they plan to redo the FT2232 with embedded EEPROM, unique hardware ID and two MPSSE channels. I hope they keep promise.

And let's hope they get mode setting right.

--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

I'm curious as to why the datasheet for the evaluation board DLP2232M states: "There are also several new modes which can be enabled in the external EEPROM, or by using DLL driver commands." Would this not imply that you can change modes by commands only and therefore do not require a EEPROM?

Thomas

The Silabs CP21xx series have on board EEPROM. It also has a PLL on board, so saves a Xtal.

Not sure about how the other finer points compare.

-jg

NO, if either of the ports needs to be in FIFO mode (245 mode) it must have an external EEPROM.

The extra modes are how many different ways the Port A serial port can be configured for standard serial/JTAG/SPI/I2C....

I still think they should have pins for basic serial/parallel for less inventory and manufacturing steps of programming several devices on board.

If they could get the driver and device to tell you what chip was at the other end of the link, let alone have driver config and version numbers reported in a better way would help.

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Paul Carpenter          | paul@pcserviceselectronics.co.uk
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Hi Paul,

The documentation for the DLP2232M says: "There are also several new modes which can be enabled in the external EEPROM, or by using DLL driver commands. These include Synchronous Bit-Bang Mode, a CPU-Style FIFO Interface Mode, a Multi-Protocol Synchronous Serial Engine Interface Mode, MCU Host Bus Emulation Mode, and Fast Opto-Isolated Serial Interface Mode."

I have the eval board on the way and will soon find out for myself. I have also asked the question to tech support at FTDI.

Thomas

There is no way to activate FIFO mode without the EEPROM

--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

You can queue up the pin change commands and send them over the USB as a bunch - it's not as fast as using the accelerated SPI modes, but at least you don't have a separate USB transaction for each change of the pin state.

It's on the reads, where you have to sequence the bit input with the clock edge outputs, that it gets very slow. There may be ways of optimising this, but I haven't found any that make much of a difference.

Paul Burke