12 Replies Latest reply on Jun 25, 2014 3:57 AM by tushar panda

    Open SDA

    tjmerics

      ANy info on getting the Open SDA interface working on the riot board ? Given the builtin usb-serial bridge this could be quite useful.

        • Re: Open SDA

          I tried getting some response using the instructions in the OpenSDA users guide from http://www.pemicro.com/opensda/ but no luck.

           

          I've heard that there will be support for it at some point, but nothing more than that.

           

          I'm not really sure how useful that usb-serial connection will be, given that most of the usefull stuff will be directed towards the debug connector at J18 by default.

            • Re: Open SDA
              tjmerics

              THe device is a composite usb device. It will support a serial port and debug port at the same time. It's not hard to redirect the console. Will only need a USB cable to get serial. Seems to me they would want at least the serial running to make things easy.

                • Re: Open SDA

                  You'd think.

                   

                  On the couple of boards I have, I get no usb devices enumerated when I connect to that port, which would appear to suggest there's either no firmware on the device, or that what's on it doesn't do the OpenSDA features.

                  Is yours any different? Do you see anything enumerated if you connect it to a PC?

                    • Re: Open SDA
                      tjmerics

                      Mine doesn't enumerate either. Hope one doesn't need a jtag programmer to install the software. SHould have been setup to use the USB boot loader. Thought this was really going to be a great board. It's very disappointing.

                        • Re: Open SDA

                          I still think it's a good board, but I don't understand what the point is in loading the OpenSDA parts without the firmware.  If jtag is needed then I suspect that very few people will bother, especially as J17 isn't installed.

                          Only other way I can see from the schematics is if it can somehow detect a specially formatted SD card in J6 and read OpenSDA firmware from there.

                            • Re: Open SDA
                              tushar panda

                              if it can somehow detect a specially formatted SD card in J6 and read OpenSDA firmware from there

                              but its connected to SPI flash.

                              Once the burn SDA_BURN_EN is active, it will interface with SPI flash rather than  SDCARD, i guess.

                              sry , i misread a bit,

                              the SD is supported SDA_SD2_DATA3.

                               

                              Screenshot1.png

                                • Re: Open SDA
                                  tjmerics

                                  except I haven't seen a board with a spi flash installed.

                                  • Re: Open SDA

                                    Yep, you could get to SPI flash, but U22 isn't populated.

                                     

                                    SDA_BURN_EN seems to be controlled by U23 itself, so presumably some OpenSDA firmware can take control of, or override the SD card. So the question is whether or not there's some bootloader already installed on U23 such that it can either boot from the SD, or do some firmware update from it ?

                                     

                                    Currently it seems that we can't get into OpenSDA bootloader mode using the instructions from the OpenSDA User Guide, so something is missing, it may just be some information we don't have, or something physically missing in the hardware, but right now we don't know what.

                                     

                                    Needing to get a soldering iron and either install U22 or J17 is going to limit it's usefulness for a lot of people

                                      • Re: Open SDA

                                        Also, I suspect that if jtag is necessary to get OpenSDA working then people with jtag hardware and experience will just plug it straight into J10 and skip the OpenSDA stuff completely...  So hopefully there's another way or having the hardware onboard is going to end up being pointless.

                                          • Re: Open SDA

                                            Looking with a scope shows that U23 drops out of reset approx every 54uS for 1.5uS, SDA_BURN_EN never seens to change. As far as I can tell no attempt is made to access an SD card and Y5 is never enabled.

                                             

                                            Going by the OSDAUG, we're supposed to hold down reset and then connect the USB cable, however POR_B from the reset button is buffered via U26 to IMX6_RST_N  at U23 pin 20. However as SDA_BURN_EN doesn't appear to ever go active then U23 would never see the state of the reset button. The conclusion therefore has to be that U23 is likely to be blank.

                                            Section 6.3 of the K20 reference manual states that the only boot source is internal flash. So if the internal flash is indeed blank and doesn't include some form of boot loader that we simply don't know how to access then we need some other way to program the chip.

                                            Programming U23 can be done via EZPort if EZP_CS is held at the appropriate point, however EZP_CS is connected to SDA_BURN_EN and not available at any connector, therefore you have to enable EZPort via jtag which you'd need to do from the un-populated J17.

                                             

                                            I really do hope there's a boot loader in there...   but even if there is the problem is how to trigger it to enable the buffers that would let us talk to the device via serial port or SD card.

                            • Re: Open SDA
                              tushar panda

                              let me check with our firmware team if there is a Open SDA support available .