topic Re: isr_vctor in KDS in Kinetis Microcontrollers

isr_vector in KDS

stdcerr — Thu, 22 Oct 2020 23:17:44 GMT

Hi,

I'm working on a project in Kinetis Design Studio using a SEGGER J-Link debugger. Now, when I run the application, KDS seemingly randomly after some time jumps to a tab that reads "isr_vector" and only shows "No source available for "__isr_vector() at 0x0" and a [View Disassembly...] button (which clicked only shows a dotted line in the Disassemby window. Sometimes, the application keeps running as if nothing had happened while other times it does stop. There is a debug console hooked up to UART0 and an RFID reader to UART4 and nothing else should be active. How do I best go about finding the seemingly misconfigured isr vector?

Re: isr_vctor in KDS

jingpan — Wed, 21 Oct 2020 07:56:43 GMT

Hi stderr,

When you go into debug mode, does the disassembly window display dotted line at address 0x0? It display something like "movs r0,r0" in my demo project.

SCB->VTOR register assign the vector table start address.

And you can check NVIC-> ISER(interrupt set enable register at 0xe000e100) and NVIC->ISPR(interrupt set pending register at 0xe000e200) to see what interrupt is happening.

Regards,

Jing

Re: isr_vctor in KDS

stdcerr — Fri, 23 Oct 2020 18:49:56 GMT

Hi Jing,

Thanks for the reply:

@jingpan wrote:
Hi stderr,
When you go into debug mode, does the disassembly window display dotted line at address 0x0? It display something like "movs r0,r0" in my demo project.

Yes, all I see is:

@jingpan wrote:
SCB->VTOR register assign the vector table start address.
And you can check NVIC-> ISER(interrupt set enable register at 0xe000e100) and NVIC->ISPR(interrupt set pending register at 0xe000e200) to see what interrupt is happening.

There is no SCB or NVIC register, the only ones I see are:

s0 is followed up with registers up to s31.

One thing I found it, that the sp register reads:

Name : sp Hex:0x0 Decimal:0 Octal:0 Binary:0 Default:0x0 <__isr_vector>

when I click on it, also the pc looks like:

Name : pc Hex:0x0 Decimal:0 Octal:0 Binary:0 Default:0x0 <__isr_vector>

all others just show 0s which I find odd.

Re: isr_vctor in KDS

jingpan — Mon, 26 Oct 2020 09:23:29 GMT

Hi,

It seems everything is crash. All registers is zero.

NVIC and SCB register can't be read in that window. You can read them in memory window by input address.

Regards,

Jing

Re: isr_vctor in KDS

stdcerr — Mon, 26 Oct 2020 21:46:49 GMT

I have the same situation now, KDS stopped, "No source available for "__isr_vector() at 0x0", All registers are 0x0 but in the disassembly window I now have:

00000000: Failed to execute MI command: -data-disassemble -s 0 -e 140 -- 3 Error message from debugger back end: Cannot access memory at address 0x0 00000001: Failed to execute MI command: -data-disassemble -s 1 -e 77 -- 3 Error message from debugger back end: Cannot access memory at address 0x0 00000002: Failed to execute MI command: -data-disassemble -s 2 -e 78 -- 3 Error message from debugger back end: Cannot access memory at address 0x2 00000003: Failed to execute MI command: -data-disassemble -s 3 -e 79 -- 3 Error message from debugger back end: Cannot access memory at address 0x2 00000004: Failed to execute MI command: -data-disassemble -s 4 -e 80 -- 3 Error message from debugger back end: Cannot access memory at address 0x4 00000005: Failed to execute MI command: -data-disassemble -s 5 -e 81 -- 3 Error message from debugger back end: Cannot access memory at address 0x4 00000006: Failed to execute MI command: -data-disassemble -s 6 -e 82 -- 3 Error message from debugger back end: Cannot access memory at address 0x6 00000007: Failed to execute MI command: -data-disassemble -s 7 -e 83 -- 3 Error message from debugger back end: Cannot access memory at address 0x6 00000008: Failed to execute MI command: -data-disassemble -s 8 -e 84 -- 3 Error message from debugger back end: Cannot access memory at address 0x8 00000009: Failed to execute MI command: -data-disassemble -s 9 -e 85 -- 3 Error message from debugger back end: Cannot access memory at address 0x8 0000000a: Failed to execute MI command: -data-disassemble -s 10 -e 86 -- 3 Error message from debugger back end: Cannot access memory at address 0xa 0000000b: Failed to execute MI command: -data-disassemble -s 11 -e 87 -- 3 Error message from debugger back end: Cannot access memory at address 0xa 0000000c: Failed to execute MI command: -data-disassemble -s 12 -e 88 -- 3 Error message from debugger back end: Cannot access memory at address 0xc 0000000d: Failed to execute MI command: -data-disassemble -s 13 -e 89 -- 3 Error message from debugger back end: Cannot access memory at address 0xc 0000000e: Failed to execute MI command: -data-disassemble -s 14 -e 90 -- 3 Error message from debugger back end: Cannot access memory at address 0xe 0000000f: Failed to execute MI command: -data-disassemble -s 15 -e 91 -- 3 Error message from debugger back end: Cannot access memory at address 0xe 00000010: Failed to execute MI command: -data-disassemble -s 16 -e 92 -- 3 Error message from debugger back end: Cannot access memory at address 0x10 00000011: Failed to execute MI command: -data-disassemble -s 17 -e 93 -- 3 Error message from debugger back end: Cannot access memory at address 0x10 ... ...

and this all while the application still runs on the MCU, I'm confused to say the least.

Re: isr_vctor in KDS

stdcerr — Mon, 26 Oct 2020 22:14:39 GMT

in fact, when the isr error kicks in, the application seems to reset and to start running from beginning but then run just fine....

Re: isr_vctor in KDS

jingpan — Tue, 27 Oct 2020 02:27:36 GMT

Hi stdcerr,

When this bug comes, cpu may also stay in unknow state and the reset condition will not happen. You must check what is wrong both in hardware and software. There is a stack window in KDS. You can see the pc position and stack status before crash.

Regards,

Jing

Re: isr_vctor in KDS

stdcerr — Wed, 28 Oct 2020 18:14:03 GMT

Yeah it in fact does not reset every time it enters this "__isr_vector() at 0x0" -mode

The Call Stack view in KDS is empty & does not show anything when it is stopped.

Re: isr_vctor in KDS

jingpan — Thu, 29 Oct 2020 06:17:51 GMT

Hi,

I can't think of any smart way to debug. If you believe this is caused by isr, you can toggle a gpio when in/out interrupt service code. Then shrink the position till find the problem.

Regards,

Jing