lm3s8962 cannot enter debug mode

[w0utje]

Hello,

I am developing an application on my luminary lm3s8962 with labview for ARM, I have an home made PCB with this ARM and sensors.

I have 2 PCB's of the same.

My problem is,

instead of a 8 MHz crystal I have a 8 MHz oscillator (single ended) so I see that my RTC is not good, I can see this with GPS timing.

but using timer0 with interval 1 sec and update a counter works good!?

I tried to make some changes in the startup file with the clock configuration:

        ; set the system clock to run at 50 MHz
        ; SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL |
        ;                SYSCTL_XTAL_8MHZ | SYSCTL_OSC_MAIN);

        LDR        R0, =0x01C00380
        BL        SysCtlClockSet

Looking in the SysCTL I see other crystal values, like 16 MHz. used value: #define SYSCTL_RCC_XTAL_16MHZ   0x00000540  // 16.0 MHz (USB), instead of 0x380

I know this is not supported, but I want it to give it a try.

I build it and flash it, but now my debugger says:

Cannot enter memory and cannot enter debug mode.

I did some reading on the internet and it says that because 16 MHz is not supported it goes into deep sleep.

I don't know if this true..

My other PCB works fine, this one is not flashed with the wrong clock.

my question is:

first priority:

Can I prevent that my program starts up in my arm, so I can flash it with the good clock configuration. OR

Can I erase the flash (with out ULINK2) in some way, so that no program starts  up and I can flash my ARM.

second priority:

Maybe someone knows how I can get the right RTC with my 8 MHz oscillator, I need a correct clock in ms.

Thank you in advance,

Wouter

[BasvanDijke]

Hi Wouter,

The questions about the flashing can be found via the following link.

http://www.keil.com/support/man/docs/ulink2/ulink2_su_flashdownloadcfg.htm

(right click on the target and click on Show Keil uVision)

About the hardware configuration you can better ask uVision, since they know more about Hardware.

Maybe this link helps.

http://www.keil.com/support/man/docs/rlarm/rlarm_ar_config.htm

Regards,

Bas van Dijke

NI Netherlands