It has been a while a lot of new Broadcom devices (cables box) that no longer have the visible JTAG ports. (recent cable boxes with SPI chip). But I think those JTAG pins should still exist. What I am trying to do is to remove the CPU (BGA). If we have the pinout of the CPU we should be able to find the trace of the JTAG and then make the connection. Even though the SPI works but I still like to use JTAG more.
Also I had someone asked me to take a look of remote programming. JP1, JP1.3. I might also do some research to see if we can make the NT work on those devices.
JTAG pins and JP1 programming.
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usbbdm
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justsomeguy
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CAPONE
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This is always Great News. Do you Mind Shareing with Use Why You Favor JTAG Over SPI. I am Sure Most members won't mind one way or the Other so long as it can Be Done But you must have a good reason to favor JTAG over SPI Programing.usbbdm wrote:It has been a while a lot of new Broadcom devices (cables box) that no longer have the visible JTAG ports. (recent cable boxes with SPI chip). But I think those JTAG pins should still exist. What I am trying to do is to remove the CPU (BGA). If we have the pinout of the CPU we should be able to find the trace of the JTAG and then make the connection. Even though the SPI works but I still like to use JTAG more.
Also I had someone asked me to take a look of remote programming. JP1, JP1.3. I might also do some research to see if we can make the NT work on those devices.
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usbbdm
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JTAG is designed for CPU. The SPI programming is normally a hack (SB5102 is different).CAPONE wrote:This is always Great News. Do you Mind Shareing with Use Why You Favor JTAG Over SPI. I am Sure Most members won't mind one way or the Other so long as it can Be Done But you must have a good reason to favor JTAG over SPI Programing.
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merkin
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Can you list specific models #'s of the cable boxes you refer to?usbbdm wrote:It has been a while a lot of new Broadcom devices (cables box) that no longer have the visible JTAG ports. (recent cable boxes with SPI chip). But I think those JTAG pins should still exist. What I am trying to do is to remove the CPU (BGA). If we have the pinout of the CPU...
Is the BGA pinout for the BCM chip in question public?
I recently acquired a couple Wegener's SMD-515 to play with, based on Sigma's SMP8634, and found this while searching for uCodes and SDk/Toolchain.(Which are available on google).
Perhaps we could get lucky like these guys...http://www.t-hack.com/wiki/index.php/EJTAG_on_SMP (Wegener left the EJTAG pins populated as well as JTAG Enable jumper on the SMD-515 PCB, so it was not an issue for me.):-D
Right now my FX2LP Dev board is renumerating as Altera's USB-Blaster with this firmware http://ixo-jtag.sourceforge.net/. Also Works with Quartus II. I think it supports SignalTap also with different firmware. Perhaps it can come in handy for you as a logic analyzer to determine undefined JTAG pinouts on unpopulated boards.
Hardware above is supported by OpenOCD and Urjtag, both of which support SMP8634. Hence the reason for choosing these tools for development just for fun with my free time.
I am sure you could get USBJTAGNT to work on SMP8634/5 (which are in numerous NMT's) in a heartbeat, but no one has requested such support. In fact here is full datasheet if interested in supporting it in the future. http://www.mediafire.com/?yfgfm3ln1t9j8ye
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