topic Re: Clock problems during debug in LPC Microcontrollers

Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:38 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 20 13:58:53 MST 2014
Hello engineers,

We trying to debug/program a lpc1114/333 but there is something wrong and we are out of ideas. We use the simple led blinky example. When programming the chip with SWD everything seams to be ok even after verifying. When we start the debug session in LPCXpresso the status change in running but the debug led is not blinking. When pauze the debugging we can't step through the program. when switching the power off and on the led starts to blink.

-The bootloader pin is high

We use the internal oscillator

---------system_LPC11xx.c------------

#define CLOCK_SETUP           1
#define SYSCLK_SETUP          1
#define SYSOSC_SETUP          1
#define SYSOSCCTRL_Val        0x00000000
#define WDTOSC_SETUP          0
#define WDTOSCCTRL_Val        0x000000A0
#define SYSPLLCLKSEL_Val      0x00000001
#define SYSPLL_SETUP          1
#define SYSPLLCTRL_Val        0x00000023
#define MAINCLKSEL_Val        0x00000000
#define SYSAHBCLKDIV_Val      0x00000001
#define AHBCLKCTRL_Val        0x0001005F
#define SSP0CLKDIV_Val        0x00000001
#define UARTCLKDIV_Val        0x00000001
#define SSP1CLKDIV_Val        0x00000001

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:39 GMT

Content originally posted in LPCWare by nerd herd on Thu Nov 20 14:10:02 MST 2014
Hi justmakeit,

Are you using the blinky example from our LPCOpen software platform? Our blinky examples tend to use an interrupt to toggle the LED while the MCU is in a while(1) loop going to sleep, which might explain why there are no lines of code for you to step through. Have you tried putting a break point in the beginning of the interrupt handler to ensure the MCU is reaching that portion of the code?

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:39 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 20 14:27:07 MST 2014
Thanks for the fast reply,

We use the example from the LPCopen platform. We tried to place a breakpoint at the systemcoreclockupdate(); function. But he wont reach the break point or blink the leds.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:40 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 20 14:31:38 MST 2014

Quote: justmakeit
We use the internal oscillator
....
#define SYSPLLCLKSEL_Val [color=#f00]0x00000001[/color]

:quest:

Are you sure?

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:40 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 20 14:44:07 MST 2014
Hi R2D2,

We changed this value to zero. But still there is no change.

we also changed this line in the main

/* Config CLKOUT, mostly used for debugging. */
CLKOUT_Setup( CLKOUTCLK_SRC_IRC_OSC );
LPC_IOCON->PIO0_1 &= ~0x07;
LPC_IOCON->PIO0_1 |= 0x01;/* CLK OUT */

We measured the clock output with our scope. but the signal is 1V.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:41 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 20 14:56:28 MST 2014
Did you comment out System-OSC Power up?

Where's your system_LPC11xx.c? In CMSIS library? Did you rebuild everthing?

Did you try to use IRC without PLL already?

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:42 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 20 15:09:22 MST 2014

Quote: justmakeit

/* Config CLKOUT, mostly used for debugging. */
CLKOUT_Setup( CLKOUTCLK_SRC_IRC_OSC );
LPC_IOCON->PIO0_1 &= ~0x07;
LPC_IOCON->PIO0_1 |= 0x01;/* CLK OUT */

We measured the clock output with our scope. but the signal is 1V.

If CLKOUTDIV is 0 (default) CLKOUT is disabled

#ifdef CLKOUT
 //enable CLKOUT
 LPC_IOCON->PIO0_1= (1<<0);
// select clock 0 IRC, 1 System oscillator, 2 Watchdog, 3 Main clock
 LPC_SYSCON->CLKOUTCLKSEL = 0;
// select clock divider
 LPC_SYSCON->CLKOUTDIV = 10;//CLKOUT Divider = 10
// Enable CLKOUT
 LPC_SYSCON->CLKOUTUEN = 0;
 LPC_SYSCON->CLKOUTUEN = 1;//
#endif

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:42 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 20 15:14:46 MST 2014
Hi R2D2,

We use the CMSISv2p00_LPC11xx imported in our workspace and rebuild everything.
We changed the defines as shown below:

#define CLOCK_SETUP           1
#define SYSCLK_SETUP          1
#define SYSOSC_SETUP          1
#define SYSOSCCTRL_Val        0x00000000
#define WDTOSC_SETUP          0
#define WDTOSCCTRL_Val        0x000000A0
#define SYSPLLCLKSEL_Val      0x00000000
#define SYSPLL_SETUP          1
#define SYSPLLCTRL_Val        0x00000023
#define MAINCLKSEL_Val        0x00000000
#define SYSAHBCLKDIV_Val      0x00000001
#define AHBCLKCTRL_Val        0x0001005F
#define SSP0CLKDIV_Val        0x00000001
#define UARTCLKDIV_Val        0x00000001
#define SSP1CLKDIV_Val        0x00000001

So the SystemInit() in the startupfile will not bypass the system oscillator and the main oscillator is configured as internal RC.

In the main() we configure the CLKOUT to be the CLKOUT_SRC_IRC_OSC (so we can measure the frequence at the CLKOUT pin?)

int main (void) {
uint32_t interval;

SystemCoreClockUpdate();

/* Config CLKOUT, mostly used for debugging. */
CLKOUT_Setup( CLKOUTCLK_SRC_IRC_OSC );
LPC_IOCON->PIO0_1 &= ~0x07;
LPC_IOCON->PIO0_1 |= 0x01;/* CLK OUT */

and we changed the LED port/pin to match the LED in our hardware.

each time we start a debug session, the proces starts running but we don't see the LED blink.
when we power off and power back on the hardware without programming the LED goes on but wont blink. (tested with different LEDs so the programming seems to work)

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:43 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 20 15:43:52 MST 2014
I'm not sure which code you are using in detail :)

Could be a good idea to copy system_LPC11xx.c in your project SRC directory (to use it local) and export / post this project...

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:43 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 27 12:18:05 MST 2014
Sorry for the late respons, we only work at this project every thursday evening.

Attached the sourcode: the blinky project and CMSIS library containing the system_LPC11xx.c

We only tried to change some configurations to match our hardware. (LPC1114/333 with only internal crystal)

At this point the debug freezes when trying to start _main at line 313 of cr_startup_lpc11.c and we think this is because of clock configurations.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:44 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 27 13:38:36 MST 2014

Quote: justmakeit
Attached the sourcode: the blinky project and CMSIS library containing the system_LPC11xx.c

After copying system_LPC11xx.c in your blinky/src folder it's working here without problems.

Your configuration is confusing, if you don't want to use PLL you can switch it off...

I'm not sure what 'debug freezes when trying to start _main at line 313' is in detail...

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:45 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 27 13:54:49 MST 2014
We have the CMSISv2p00_LPC11xx project added as reference to the Blinky project and added both to the workspace so we don't have to copy the system_LPC11xx.c to the Blinky project if I'm right.

we changed the configuration a bit:

- disabled SYSOSC_SETUP because we only want to use IRC clock
- MAINCLKSEL is still the IRC clock

we have a 2K2 connected between P0_1 and VCC to prevent the IC from going into bootloader mode.
P0_1 is also configured as CLKCOUT for the IRC clock but we only measure a constant 3V3 at this pin.

When we start debugging in LPC Expresso the program holds and shows SIGTRAP.

See attached picture.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:45 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 27 14:34:39 MST 2014

Quote: justmakeit
When we start debugging in LPC Expresso the program holds and shows SIGTRAP.

:quest:

Then use Single Step to line 106... There's your problem starting...

To avoid problem you should comment out CLKOUT setting and all timers.

Try to run a very simple program, just toggling Pins...

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:46 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 27 15:17:23 MST 2014
We just found out that programming is not the issue, after programming and starting debug, the debug freezes.
When we disconnect the power and programmer and connect this again the Blinky program starts and the LEDs light up.

each change in out program works after stopping debug and reconnecting the power and programmer to the IC.

we now know the code is correct but don't understand why the debuging is freezing the IC.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:46 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 27 15:21:50 MST 2014

Quote: justmakeit
We just found out that programming is not the issue...

So it's a hardware problem and time to check your schematic / board...

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:47 GMT

Content originally posted in LPCWare by justmakeit on Thu Nov 27 15:40:54 MST 2014
True, before we start searching to a difference between schematic and board, is our schematic for use with SWD debugging ok?

Is for example the SWO pin needed for debugging?

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:47 GMT

Content originally posted in LPCWare by R2D2 on Thu Nov 27 15:57:50 MST 2014

Quote: justmakeit
True, before we start searching to a difference between schematic and board, is our schematic for use with SWD debugging ok?

SWO isn't necessary...

I'm using a simple SWD connection with GND / SWCLK / SWDIO / Reset without problems...

I'm not sure if you are using a Link or Link2...

Your SWD connection is correct, but I would recommend to use 10k pull-ups at PIO0_1 (ISP) and Reset.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:48 GMT

Content originally posted in LPCWare by justmakeit on Sat Nov 29 06:13:51 MST 2014
The 10K at PIO0_1 we already added afterwards, we can increase the 2K2 of the reset pin.

The 10K required at the ISP pin we learned the hard way in a previous project after days of searching :P

Thanks for all the feedback, we start to get a good idea of the problems.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:49 GMT

Content originally posted in LPCWare by justmakeit on Thu Dec 11 13:51:37 MST 2014
We just soldered a second PCB, this time with an external 12MHz crystal attached.
We started with a fresh Blinky project and didn't change a single line of code.

Unfortunately the same problems occur:
Programming seems to go ok but again when the debugging starts a SIGTRAP message occurs and the CHIP doens't do anything.
Measuring at both the CLK pins shows a flat line.

After powering off and on of the supply power we measure a clean 12MHz on the clock pins.

Any suggestions?

See attached images for our debug config and the SIGTRAP message.

Re: Clock problems during debug

lpcware — Wed, 15 Jun 2016 19:23:49 GMT

Content originally posted in LPCWare by TheFallGuy on Thu Dec 11 14:03:43 MST 2014
Which debug probe are you using?

Looks like your code has taken an exception during startup code (0xfffffff9 is the stack marker for an exception handler). Suggest you set the initial breakpoint on ResetISR. And single step to find out what is causing the exception.