Kinetis MicrocontrollersのトピックRe: Measuring clock in KEA-128

Measuring clock in KEA-128

vigneshbalaji — Mon, 18 Jan 2016 18:08:26 GMT

Hi,

I want to measure my clock in KEA-128.I am doing this by toggling a GPIO pin in it.I am running my clock at 20Mhz which was the standard example given by NXP(Freescale).But my scope is reading only 583 Khz only.I think I am missing something in it.

I want to know the bus clock per instruction in KEA-128?

The clock per instruction of peripherals?

Can you suggest me a good method to measure the Clock of KEA-128 other than toggling a GPIO?

Re: Measuring clock in KEA-128

davidsherman — Mon, 18 Jan 2016 18:58:40 GMT

I would suggest using the FlexTimer in PWM mode, and have it toggle one of the outputs. It uses bus clock as the clock source and is much more straightforward than disassembling the source and computing instruction cycles. Not all instructions use the same number of clock cycles.

Re: Measuring clock in KEA-128

Alice_Yang — Tue, 19 Jan 2016 04:38:11 GMT

Hello Vignest,

You can check the bus clock on the pin of PTH2 .

First enable the "bus clock output " of this register :

SIM_SOPT0 -> CLKOE

Hope it helps !

Have a great day,
Alice Yang

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Re: Measuring clock in KEA-128

vigneshbalaji — Tue, 19 Jan 2016 07:27:13 GMT

Hi Alice and David,

Both of your answers are working for me.I want to know why normal GPIO toggling won't work.Is it because of number of instructions taken to do it?

Can you please provide any diagram or place where it is mentioned that PTH2 is directly connected to the system clock.Thank you ffor your help.

Re: Measuring clock in KEA-128

vigneshbalaji — Tue, 19 Jan 2016 12:32:50 GMT

Hi,

Is there a constrain that we should not run the bus clock at 48Mhz???

I modified my clock like this and found that my controller is not in a flashable state.

Can you tell me what has happened behind this?I am not able to flash my controller after this?

This was my clock code

SIM_SOPT0 = SIM_SOPT0_CLKOE_MASK;

void Clk_Init()

{

ICS_C1|=ICS_C1_IRCLKEN_MASK; /* Enable the internal reference clock*/

while(!(ICS_S & ICS_S_LOCK_MASK));

ICS_S |= ICS_S_LOCK_MASK ; /* Clear Loss of lock sticky bit */

}

Re: Measuring clock in KEA-128

davidsherman — Tue, 19 Jan 2016 13:22:33 GMT

The bus clock cannot run faster than 24MHz. You will have to change the SIM_CLKDIV register to make sure the bus clock is divided by 2 from the core clock BEFORE you set the ICS for 48MHz.

Re: Measuring clock in KEA-128

Alice_Yang — Wed, 20 Jan 2016 02:53:01 GMT

Hello VIGNESH,

- How about your code to toggling the GPIO pin ?

- About the bus clock output , please refer to the KEA128RM, the PTH2 pin is the bus clock pin,

and configure the "CLOKOE" and "BUSREF" to select the value of the pth2 pin out put.

Hope it helps

Have a great day,
Alice Yang

Re: Measuring clock in KEA-128

kerryzhou — Wed, 20 Jan 2016 06:09:08 GMT

Hi VIGNESH BALAJI,

See you again!

Actually, about this question, I already answer you in your CASE:

GPIO toggle is using the GPIO module, the GPIO module speed is not as faster as the bus clock.

Besides, if you use the GPIO, it still related to the instuction cycles, the compilier, the optimization function,ect.

All these factors will affect the GPIO toggle speed, you can check the according asm code, you will find the detals. If you still want to use GPIO, you can choose FGPIO, it will faster than the GPIO. Write the code, don't use the while, because while still need a lot of cycles, you can use the FGPIO code one by one directly.

eg.

FGPIOE_PRTOR=0X02;

...

But I suggest you use the method which I told you to test the bus clock:

Configure SIM_SOPT0[CLKOE]=1, SIM_SOPT0[BUSFREF]=0, Bus clock output is enabled on PTH2.

This will output bus clock directly!

Wish it helps you!

Have a great day,

Jingjing

Re: Measuring clock in KEA-128

vigneshbalaji — Wed, 20 Jan 2016 08:44:29 GMT

Thank you jing,

The FTM method was good

Re: Measuring clock in KEA-128

kerryzhou — Wed, 20 Jan 2016 09:18:15 GMT

OK, that's very good!

If you still have any question, please let me know!

Have a great day,

Jingjing

Re: Measuring clock in KEA-128

vigneshbalaji — Wed, 20 Jan 2016 10:10:45 GMT

Hi Jing,

I am having a problem now.I ran my bus clock at 48 Mhz using the below code change.Now I am not able to flash my code.Can you tell me what went wrong and how to fix it?

SIM_SOPT0 = SIM_SOPT0_CLKOE_MASK;

void Clk_Init()

{

ICS_C1|=ICS_C1_IRCLKEN_MASK; /* Enable the internal reference clock*/

while(!(ICS_S & ICS_S_LOCK_MASK)); /* Wait for PLL lock, now running at 40 MHz (1280 * 31.25Khz) */

ICS_S |= ICS_S_LOCK_MASK ; /* Clear Loss of lock sticky bit */

}

This was the error message I got.I am using segger to Flash the code.

Re: Measuring clock in KEA-128

davidsherman — Wed, 20 Jan 2016 14:42:03 GMT

How are you flashing it? Are you using the debugger or the "flash from file" utility? It appears this is the same code that set it for 48 MHz; where are you setting the SIM_CLKDIV register? If you set a breakpoint before Clk_init is called, does it stop at the breakpoint if you try debugging? From the error message it just looks like it stopped debugging, which is to be expected if you are attempting to run the bus at 48MHz.

Re: Measuring clock in KEA-128

vigneshbalaji — Wed, 20 Jan 2016 14:59:13 GMT

Hi,

I am using the Debugger to flash it,which internally uses SWD.I saw that SWD cannot run above 24 Mhz but now my controller bus clock is running at 48Mhz.Can you tell me what to do now to Flash my controller again?

Th code is not even Flashing so I am not able to debug it.

Re: Measuring clock in KEA-128

davidsherman — Wed, 20 Jan 2016 15:07:57 GMT

As I said, you CANNOT run the bus at 48 MHz, the KEA128 will stop functioning and the debugger will stop working once the code you are showing sets the clock for 48MHz. You will have to correct your code first and flash it with the correct code in order to debug.

Re: Measuring clock in KEA-128

vigneshbalaji — Wed, 20 Jan 2016 15:45:49 GMT

Hi David,

I corrected my code and then only I flashed it.Please check the code Below.It is the standard Example given by NXP.Still I am facing the same problem.

void Clk_Init()

{

ICS_C1|=ICS_C1_IRCLKEN_MASK; /* Enable the internal reference clock*/

ICS_C3= 0x90; /* Reference clock frequency = 31.25 KHz*/

while(!(ICS_S & ICS_S_LOCK_MASK)); /* Wait for PLL lock, now running at 40 MHz (1280 * 31.25Khz) */

ICS_C2|=ICS_C2_BDIV(1) ; /*BDIV=2, Bus clock = 20 MHz*/

ICS_S |= ICS_S_LOCK_MASK ; /* Clear Loss of lock sticky bit */

}

I even added a divider SIM_CLKDIV = 0x11100000 before the clock.Can you tell me what to do to Flash the code to my Microcontroller.

;

Re: Measuring clock in KEA-128

davidsherman — Wed, 20 Jan 2016 16:56:47 GMT

What happens if you use the flash utility and not the debugger?

Re: Measuring clock in KEA-128

vigneshbalaji — Wed, 20 Jan 2016 17:18:17 GMT

My debugger can do both debug and Flash also.I am not able to Flash with it Right now.Is there any way out to make my Controller Flash Again?

Re: Measuring clock in KEA-128

davidsherman — Wed, 20 Jan 2016 17:26:02 GMT

What happens if you use the flash utility and NOT the debugger? (Hint: Try using the "Flash From File" utility, and don't use the debugger)

Re: Measuring clock in KEA-128

vigneshbalaji — Wed, 20 Jan 2016 17:33:00 GMT

The same error. I just tried to Flash the code(Run) the same thing is happening.Can you tell me the reason behind this?

I want to know whether all the Flashing is through SWD in the ARM Cortex-M0+.Is there any way where we can Flash the code without the SWD interface of Cortex M0+?

Re: Measuring clock in KEA-128

davidsherman — Wed, 20 Jan 2016 17:47:50 GMT

What messages do you see in the console window? Does it report that it's erasing and programming? Yes, you do have to use SWD, that's the only means of programming the flash since that part doesn't support JTAG. Only other things I can suggest, when I've seen similar problems:

- Removing all breakpoints in the debugger window
- Restart computer

Edit: Disregard my question about the error, I misread the screen shots.