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Hi All, I am using the DP256. I am using the COP reset to initiate a desired reset at times, but I am also trying to use it to detect corrupted firmware (the application is field programmable firmware upgradable with protected firmware permanent). I was planning on detecting the difference by writing data to a ram location during normal firmware running that I could check after the COP reset, but this ram is being reset with the COP reset, and I am trying to work out whether the COP reset will generate a hardware reset of RAM locations, or whether it is the startup code on the C compiler I am using. Unfortunately I have been unable to find any data sheets with information on the RAM status after a COP reset. If someone can answer this question for me, or point in the direction of relevant documentation, that would be appreciated. Thanks, Adrian |
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HCS12 COP Reset
Started by ●July 15, 2004
Reply by ●July 16, 20042004-07-16
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"Adrian Vos" vosadrian@y wrote COP reset, like other resets, doesn't clear RAM. Edward > Hi All, > > I am using the DP256. I am using the COP reset to initiate a desired reset > at times, but I am also trying to use it to detect corrupted firmware (the > application is field programmable firmware upgradable with protected > firmware permanent). I was planning on detecting the difference by writing > data to a ram location during normal firmware running that I could check > after the COP reset, but this ram is being reset with the COP reset, and I > am trying to work out whether the COP reset will generate a hardware reset > of RAM locations, or whether it is the startup code on the C compiler I am > using. Unfortunately I have been unable to find any data sheets with > information on the RAM status after a COP reset. If someone can answer this > question for me, or point in the direction of relevant documentation, that > would be appreciated. > > Thanks, > > Adrian |
Reply by ●July 16, 20042004-07-16
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Thanks for the responses all!! I had an error in my macros, and the ram location I was using was a general global variable in the compilers ram space rather than a ram variable I manually located (like a register). Metrowerks by default initialises the ram space of variables it allocates in the startup code, so it was being reset. Now that I have located it manually, it is not being reset, and I can achieve what I was after. In my case I initialise this variable to 0 on the power on reset vector, I then set it in the general firmware. If the firmware is corrupt data, the variable will not be set, and I can check this in the COP vector to see if the COP resulted from a planned reset or from corrupt code. Thanks again!! -- Adrian ----- Original Message ----- From: "Edward Karpicz" <> To: <> Sent: Friday, July 16, 2004 4:43 PM Subject: Re: [68HC12] HCS12 COP Reset > "Adrian Vos" vosadrian@y wrote > > COP reset, like other resets, doesn't clear RAM. > > Edward > > > Hi All, > > > > I am using the DP256. I am using the COP reset to initiate a desired reset > > at times, but I am also trying to use it to detect corrupted firmware (the > > application is field programmable firmware upgradable with protected > > firmware permanent). I was planning on detecting the difference by writing > > data to a ram location during normal firmware running that I could check > > after the COP reset, but this ram is being reset with the COP reset, and I > > am trying to work out whether the COP reset will generate a hardware reset > > of RAM locations, or whether it is the startup code on the C compiler I am > > using. Unfortunately I have been unable to find any data sheets with > > information on the RAM status after a COP reset. If someone can answer > this > > question for me, or point in the direction of relevant documentation, that > > would be appreciated. > > > > Thanks, > > > > Adrian > > Yahoo! Groups Links |
