Review of FlashLINK JTAG interface

[petemate]

Hi guys, I need JTAG access to some old hardware and found the original software for programming said hardware. Its an ST PSD4235G2V, in case anyone is wondering.

Anyway, the old software supports a FlashLINK JTAG interface, which is really simple to make. So I copied the design and would like your inputs on the few changes I have made.

There are two versions of the old design:

https://media.digikey.com/pdf/Data%20Sheets/ST%20Microelectronics%20PDFS/FL-101.pdf (from 2002)

http://www.manley.com.cn/web/admin_ml32/pic/down/200882917341835980.pdf (From 2003)

It looks as though they re-did the design in 2003, but forgot a few things: A 100pF capacitor on a line and they changed shorting DB13 to DB8 to DB13 to DB20 instead. I believe this is a mistake and I found a forum post elsewhere that mentions this as a mistake. So I added a solder bridge to fix this, in case its needed.

Anyawy, I made a few other changes that I'd like you guys to review.

• They use 74A240/74VHC240, which are inverting buffer/drivers for U1. Since I couldn't get those from JLCPCB, I decided to use 74HC244 instead. That is a non-inverting buffer/driver. I believe the two cascaded inverters to be equal to my non-inverting solution. Is that correct?
• They use DM54ALS05A or 74AC05 for all the inverters, which are open-collector inverters. Again, I couldn't get that, so I decided to use 74HC04, which are push-pull versions. To make them open-collector compatible, I added a PNP transistor on the output. Any issues with this? 
• They use the signal JEN to control whether or not U1 should enable the outputs. The signal is inverted twice and is again open-collector. Since I had a spare buffer in U1, I decided to use that to buffer JEN instead of the double inverter, as this saves me an IC. However, I ran into the same open-collector vs push-pull problem and added a PNP transistor.
• I used 33 ohm resistor networks instead of 47 ohm ones.

Please let me know if you spot anything else!


Thanks for your help!

[CJay]

Should also work for PSD103 which I have a need for, what software are you going to use?

[petemate]

Should also work for PSD103 which I have a need for, what software are you going to use?

PSDSoft Express. It is freely available from the ST web page. Only problem is that I have to run it in an windows xp virtual machine and that the JTAG thingie works on a parallel port. So i'd have to get a parallel port interface or install on an old computer(probably the latter).

It doesn't appear that PSDSoft express supports anything below PSD3xx, though. You're welcome to get a copy of the design when its done.

[Peanut1996]

Hi,I need PSDsoft express version that support programming PSD311 and DLPortIO driver.Do you have them?Thanks.

[tru]

@petemate, I don't know if JEN is important, but I think your Q3 PNP is incorrect because it will invert.  In the 2002 link schematic there is a cascade of 2 invertors so basically no inversion.
I have built one long ago and used these instead:
SN74ACT240 (TI) in place of 74A240 or 74VHC240
MC74ACT05DG (onsemi) in place of DM54ALS05A or 74AC05

Also, yes you do need to short DB13 to DB8 instead.

@others, the circuit will not work on PSD3xx because these do not have a JTAG interface, instead a proprietary programming pins so you need a WSD Magic Pro Programmer + PLCC adapter socket.

[tru]

Correction: WSI MagicPro Programmer + PLCC adapter socket

[petemate]

hi @tru, thanks for your reply - even if it is a bit late

Everything seems to be working with the implementation - I'm able to program and read back PSD ICs using PSDsoft Express.

May I ask what work you did with the device? I'm trying to repair an TTI TGA12101 which had a bad firmware update, but I can't overwrite the original PSD memory without also clearing the PLD information - and I don't have that. So I reverse-engineered the PLD setup, which I believe basically only does external chip enables, got some blank PSDs online and replaced them in the unit. I'm able to get the unit up and running with peripherals controlled by the PSD, but I end up in some infinite loop when the unit tries to load the default waveform. Its as if its missing something, searching in the wrong memory location or, as I suspect, has some of the PSD memory incorrectly allocated. This is a real long shot, but seeing as you are from the UK, perhaps you worked for TTI at some point in time and remember utilizing those PSDs? Thanks

[tru]

I used it to repair some old temperature controllers - the manufacturer still exists so best I don't mention.  They use a Motorola MC68HCx + PSD834 to interface with the LED display, temperature and optocoupler safety circuits (buttons and relay directly via the MC68Hx).  The PSD834 usually goes bad, but I had other working units to read from and programmed to blank PSD.

There is a model using a MC68HC811E2 + PSD302 but I gave up on that one - I needed a suitable programmer + older 8.66 PSDSoft Express, just like Peanut1996.

Yes in the UK but never worked for TTI.

[Peanut1996]

@tru,If you want programmer.I could find it for you.Could you try to find the software?

[petemate]

Yes in the UK but never worked for TTI.

Thanks anyway - I was just day-dreaming for an easy fix to the issue

[Peanut1996]

@tru I've got the V8.10 and programmed successfully!