New USB chip for fast FPGA bitstream download

Antti Lukats wrote: : New 3rd generation USB interface chip FT2232C : has special high speed sync serial modes that allow very fast 1Mbit+ : downloads of FPGA configuration streams.

: there are lots of FPGA boards that use similar feature with old : (second generation) FTDI chips, the new chip looks pretty much better : specially for FPGA designs as also interfacing to FPGA logic fabric : can be implemented more efficiently.

: hope this is not out of topic, at least I was almost going to design a : similar FPGA board (with FT245BM as bootloader), now I would defenetly : use the FT2232C.

: the chips seems to be very new, so the best is to search google on : FT2232C : at least one supplier promises samples from stock already.

Before you doing so, look around on

There already is a solution with the CY7C68013 and a cyclone for PC configuration download and Usb communication with a complete toolchain.

The site seems not to be linked, so look also at

and

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

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

thanks this site is really interesting when you get into the non-linked pages :)

well CY7C68013 is already "old player" in the field, and I sure know it, my arguments for FT2232C are

• smaller package 48 vs 128 TQFP

• NO FIRMWARE

• NO DRIVERS (all free and available win+linux+mac)

• Cheaper

so depending what you are doing you have to choose. in cases where today FT245BM is used as FPGA downloader use of FT2232C would bring new advantages.

antti PS I am actually not very much fan of FTDI I would prefer to see the new functions of FT2232C in

or use

F320 as bootloader that is very tiny chip MLP28 and includes onchip USB clock generator!!! it mounts completly below the USB connector :)

If they went to the trouble of designing a new generation USB-serial chip with a high-speed sync mode, why didn't they make it capable of at least 8 Mbps? :-(

"Antti Lukats" escribió en el mensaje news:bvih81$6q8$07$ snipped-for-privacy@news.t-online.com...

well

at

According to the datasheet, when the port is configured as a synchronous FIFO (as the FT245) it uses the same prescaler as the UART configuration, and it is capable of delivering 3Mbaud. (I guess the clock is derived dividing the base oscillator frequency by 2). However, the FT2232C has a new bit-bang interface at port A called MPSSE (Multi-Protocol Synchronous Serial Engine), which is a JTAG/SPI lookalike + GPIOs configuration capable of

*5.6Mbits*.

The really nice thing about the FT2232C is that it has 2 configurable ports, with enhanced overall features. We just finished designing a programmer/debugger for one of our products

that uses one channel of the FT2232 as muxed JTAG for ARM debugging and FPGA configuration, and the second channel for serial communication (eg debug monitor and Flash programming). The FT2232C also makes it easy to power the main board and programmer through the USB's 5 volts, so it is really a 3-in-1 combo.

Regards.

-- PabloBleyerKocik /"But what... is it good for?" pbleyer / -- 1968 Engineer at IBM's Advanced Computing @embedded.cl / Systems Division, commenting on the microchip

hm good question, I was going to say its not possible in FS mode, but well peak bitrate is 12M so the sync serial should be able to pass it through at full speed. Well I have to admit I havent fully checked out the precise specs, so maybe its little more. Another thing is sustained average bit rate, that is always way smaller than max peak bit rate. 1Mbit average bit rate isnt so bad, but agree 8 would be better.

I guess only non HS USB microcontroller that could configure FGPA with highest bitrate (12Mbit bit peak) is the uPSD from

it has user programamble PLD inside the usb microcontroller so if that is programmed for continous shift, ah (I an blblabullshit) - any USB micro with SPI interface would get better than 1Mbit peak config download rate.

antti

If you dont mind just one more

According to the datasheet, when the port is configured as a synchronous FIFO (as the FT245) it uses the same prescaler as the UART configuration, and it is capable of delivering 3Mbaud. (I guess the clock is derived dividing the base oscillator frequency by 2). However, the FT2232C has a new bit-bang interface at port A called MPSSE (Multi-Protocol Synchronous Serial Engine), which is a JTAG/SPI lookalike + GPIOs configuration capable of *5.6Mbits*.

The really nice thing about the FT2232C is that it has 2 configurable ports, with enhanced overall features. We just finished designing a programmer/debugger for one of our products

that uses one channel of the FT2232 as muxed JTAG for ARM debugging and FPGA configuration, and the second channel for serial communication (eg debug monitor and Flash programming). The FT2232C also makes it easy to power the main board and programmer through the USB's 5 volts, so it is really a

3-in-1 combo.

Regards.

-- PabloBleyerKocik /"But what... is it good for?" pbleyer / -- 1968 Engineer at IBM's Advanced Computing @embedded.cl / Systems Division, commenting on the microchip

... with the ft245bm i can do transfers at a real 1 mbyte/sec from my win appl .. the 232 version is a bit slower .. KB