Hi Guile, I may be misunderstanding the problem. You made the comment: >It looks like this behavior is 'by design' so there is no other workaround >than switching off the unit. Philips followed up: >Even clearing of watchdog flag in user application may not help (if >timeout is too small) because the bootloader runs before application. For purposes of ruling out watchdog issues in problem I am looking into, I want to recreate the above watchdog problem. My sample code sets up the watchdog to trigger in minimum time, and does nothing but wait for the watchdog to trigger. In had no problems getting back to ISP with this code on my 2292. I did not need to switch off. I wanted to try this on your board. If it works without need to switch off, then my understanding of the problem is incorrect. If it does need you to switch off, then the problem may be specific to the part of version of boot loader. I like to find out which of the above is the case. Regards, Jaya Send instant messages to your online friends http://au.messenger.yahoo.com
Bootloader not always invoked after reset with P0.14 low
Started by ●February 6, 2006
Reply by ●February 25, 20062006-02-25
Reply by ●February 25, 20062006-02-25
OK. I'll run your code. What is exactly what you want me to report about it? Whether it can call the bootloader without a power-on reset? Guille --- In lpc2000@lpc2..., Jayasooriah <jayasooriah@...> wrote: > > Hi Guile, > > I may be misunderstanding the problem. > > You made the comment: > > >It looks like this behavior is 'by design' so there is no other workaround > >than switching off the unit. > > Philips followed up: > > >Even clearing of watchdog flag in user application may not help (if > >timeout is too small) because the bootloader runs before application. > > For purposes of ruling out watchdog issues in problem I am looking into, I > want to recreate the above watchdog problem. > > My sample code sets up the watchdog to trigger in minimum time, and does > nothing but wait for the watchdog to trigger. > > In had no problems getting back to ISP with this code on my 2292. I did > not need to switch off. > > I wanted to try this on your board. If it works without need to switch > off, then my understanding of the problem is incorrect. If it does need > you to switch off, then the problem may be specific to the part of version > of boot loader. > > I like to find out which of the above is the case. > > Regards, > > Jaya > > Send instant messages to your online friends http://au.messenger.yahoo.com >
Reply by ●February 26, 20062006-02-26
--- In lpc2000@lpc2..., "Guillermo Prandi"
<yahoo.messenger@...> wrote:
>
> OK. I'll run your code. What is exactly what you want me to report
> about it? Whether it can call the bootloader without a power-on reset?
>
Yes, that will do. Thanks.
Jaya
Reply by ●February 28, 20062006-02-28
Jaya: with your code, bootloader is not invoked if the reset/P0.14 signals don't run along with a power on. This was the expected behavior, isn't it? Guille --- In lpc2000@lpc2..., Jayasooriah <jayasooriah@...> wrote: > > Hi Guile, > > I am looking at what appears to be a different manifestation of the problem > you encountered in that power cycling is required to recover form a lockup > in order to transfer control to ISP by pulling P0.14 low. > > Philips explains this happens can if "timeout value is too small". The > user manual seems to say writing anything less than 0xff will result in > minimum timeout of PCLK x 256 x 4. > > The test code below then should create the lockup scenario, but it does not > on my 2292. I cannot see where I got it wrong. > > Can you try this on your board please? > > Thanks. > > Jaya > > GNU Source: > > >@ =====================================================================> >@ Interrupt Vectors > > > > .code 32 > > > > @ entry points vector > >start: > > ldr pc, =error > > ldr pc, =error > > ldr pc, =error > > ldr pc, =error > > ldr pc, =error > > ldr pc, =error > > ldr pc, =error > > ldr pc, =error > > > > .ltorg > > > >@ End of Interrupt Vectors > >@ =====================================================================> > > > > >@ =====================================================================> >@ Error Scenario > > > > .code 32 > > > >error: > > @ force reset > > ldr r0, =WATCH_DOG > > mov r1, #3 > > str r1, [r0, #0] > > str r1, [r0, #4] @ WDTC = 3 > > mov r1, #0xaa > > str r1, [r0, #8] @ WDFEED = 0xaa > > mov r1, #0x55 > > str r1, [r0, #8] @ WDFEED = 0x55 > > b . > > > >@ End Error Scenario > >@ =====================================================================> > HEX Binary: (vectors not check-sum patched) > > >:1000000018F09FE514F09FE510F09FE50CF09FE5D8 > >:1000100008F09FE504F09FE500F09FE504F01FE580 > >:10002000240000000E02A0E30310A0E3001080E50E > >:10003000041080E5AA10A0E3081080E55510A0E3A5 > >:08004000081080E5FEFFFFEA55 > >:00000001FF > > > >Message: 17 > > Date: Thu, 23 Feb 2006 12:30:37 -0000 > > From: "Guillermo Prandi" <yahoo.messenger@...> > >Subject: Re: Bootloader not always invoked after reset with P0.14 low > > > >Hi, Jayasooriah. Indeed the watchdog is the problem. At this stage of > >development I am only using the watchdog to provide a software reset > >function. Apparently this behavior is triggering only after using > >this function. And yes, you are right; the bit should be cleared by > >the external reset. > > > >It looks like this behavior is 'by design' so there is no other > >workaround than switching off the unit. > > > >Guille > > > >Message: 8 > > Date: Thu, 23 Feb 2006 23:28:38 -0000 > > From: "philips_apps" <philips_apps@...> > >Subject: Re: Bootloader not always invoked after reset with P0.14 low > > > >The bootloader does not look at the RISR register. It looks at the > >WDTOF flag in WDMOD register. > >Even clearing of watchdog flag in user application may not help (if > >timeout is too small) because the bootloader runs before application. > > > > Send instant messages to your online friends http://au.messenger.yahoo.com >
