A complette schematic of Hantek / Tekway hw revision 1.02 and 1.0.3
Hm. Why CPLD? Why not FPGA only? Did they save some pins? They seem to have XBUS which is quite wide.
Tinhead - I am speechless... all I could say is, thank you for your work and support to make this wide screen DSO so valuable.
Xbus seems to be 16 bit + 3 bit control, all these CPLD pins are on input (when i disable FPGA).
Address counter probably triggered by FPGA, i have to check that in detail.Maybe XBUS is a 16-bit muxed address/data bus, with r/w, strobe, and mode (or r/w, address strobe, data strobe), also in charge of access to the logic analyzer stuff?
Just my guess, though... You might have to put a logic sniffer to see what's going on between the FPGA and the CPLD.
There is a possibility to write alternative software from scratch. Worst case scenario is developing FPGA firmware from scratch too. It is not possible for CPLD and it is unwise to reflash CPLD.
The good thing is that there's no need to use CPLD to talk to the ADC. But there will be no memory buffer.
BTW, do these low-memory scopes have CPLD too? I noticed that Atten doesn't have a SRAM chip on the board, just empty place. Is it possible that CPLD is turned off in short-memory mode?
as we speek about software, do you got my PM about SDK?
The good thing is that there's no need to use CPLD to talk to the ADC. But there will be no memory buffer.
in current design no because the data will be shifted over CPLD, there is no physical data bus connection
between SoC and FPGA.
BTW, do these low-memory scopes have CPLD too? I noticed that Atten doesn't have a SRAM chip on the board, just empty place. Is it possible that CPLD is turned off in short-memory mode?
no idea, i know that Atten CML does have one, but never saw the bottom side of CAL model.
Turned off for sure not, you will not find even single resistor which don't need to be populated.
tinhead
Can it be fixed booting bug in the CPLD with
self-calibration relay ?
I would really appreciate a tutorial!
Nice thanks!
What about de/re-soldering the BGA, then?
What?!?
I am curious to know how do you do that?
I think is is time for a short tutorial on the BGA and Flat Pachage rework process, using home equipment:
Equipment used: A hot-air rework station, a soldering iron, soldering wick (ERSA 2mm/3mm/4mm wide), flux paste (I prefer the RMA flavor but I've only found a no-clean syringe container at the local stores -that is fine for this job), SMD rework solder-wire (sub-millimeter Alpha-Fry 62/36/2) and flux soldering paste (EDSYN 62/36/2 no-clean).
Remember that the activated flux (RA/RMA) based products have only a few months self-life, even if stored in the refrigerator.
This is the rework strategy:
1. Preheat the PCB using 130 degrees hot air for 2-3 minutes, to avoid any thermal expansion artifacts,
2. Use conventional (kitchen) aluminium foil to protect the surrounding components, by cutting off a small window to expose ONLY the target chip to the hot air flow,
3. Desolder the BGA using 300..320 degrees hot air, remove the chip and wait for everything to cool down,
4. Clean the old solder, holding the BGA package in a small plastic vice using solder wick and lots of flux; always clean the used flux (I use medical alcohol of 95 degrees or better),
5. Clean the PCB, as above,
6. Reball the BGA with the soldering iron, Ag-containing solder-wire (I use 62/36/2) and lots of fresh flux; always clean the used flux,
7. [Optional step] Reverse the PCB (that takes tiiiiiiime...),
8. Reball the PCB pads as well, as in step (6), since chip re-balling has not provided the pads with enough solder,
9a. Carefully apply flux soldering paste on the PCB pads only and flux at the chip pads, or
9b. Apply flux in lack of flux soldering paste,
10. Carefully place the BGA package on the PCB (in a single move, if possible) and
11. Preheat the whole PCB area around the chip using 130 degrees hot air for 2-3 minutes,
12. Raise the hot air temperature at 280..300 degrees and apply it to the chip in a slow circular motion,
13. Wait for the molten solder surface tension to move the chip in place when the solder melts,
14. Tap the chip gently towards the PCB, to make sure that all its pads are in contact with the solder underneath,
15. Remove the hot air and wait for everything to cool down naturally (by themselves); always clean the used flux, and
16. Done! Power the device up.
Right now I am at the seventh step...
NOTE: It is not as difficult as it sounds to be; but you need to practice enough before daring to touch your actual device without destroying it!
A second note is about the chip size: As a rule of thumb, use a hot air nozzle of half the diameter of the chip size. For chips smaller than 20mm x 20mm you may skip the PCB preheating step, only if the PCB is very thin. Unfortunately, this is not the case with Rigol's mainboard.
A third and very important note: Always know what you are doing. Always use your common sense! Miracles happen only in fairy tales...
Finally, remember that a good tool is NEVER expensive enough to have it. Just consider the possible extra cost of a damage done by using cheap ("affordable" in the marketing jargon) tools...