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Number of Timer

tran
Associate II
Posted on December 12, 2008 at 10:47

Number of Timer

5 REPLIES 5
tran
Associate II
Posted on May 17, 2011 at 12:56

Hello everybody!

I have a question about the number of timer of STM32-CORTEX M3.

We are using a STM32F101R6 ,after the datasheet on this site, this is a mic who has 32Kb flash and 6Kb in SDRAM, '' Acess Line''. So he has only 2 timer ( from the datasheet).

But when i use the library of STM32, i can use 3 timer at one time ( i defined TIM TIM1 TIM2 TIM3). is it normal?

Its the first time i work with this STM32, Could you give me some experiences about the design of software pls? What is the important things that i have to work more carefully?

Thanks

st3
Associate II
Posted on May 17, 2011 at 12:56

Quote:

But when i use the library of STM32, i can use 3 timer at one time ( i defined TIM TIM1 TIM2 TIM3).

Are you sure you can actually use the 3rd timer?

There's nothing to stop you defining those symbols - they just won't work if the actual hardware isn't there!

tran
Associate II
Posted on May 17, 2011 at 12:56

I'm very sure about it.

I defined like this in the file ''stm32f10x_conf.h''

/************************************* TIM1 ***********************************/

#define _TIM

/************************************* TIM ************************************/

#define _TIM1

#define _TIM2

#define _TIM3

And then in my application

i use TIM1 for my time base

TIM2 to create a signal output PWM 500Khz

TIM3 is used to create 4 signals PWM with the periods differents.

and EVERYTHING works very good when i observe by the debugger CPY-debugger ( from IAR workbench) via JLINK.

I thought it was because of Jlink who generate TIMER, but everything is the same when i disconnect the debugger from my hardware?

so what is the point?

Technically, the TIM1 can't work because his adresse is in zone RESERVED

???

abraxa
Associate II
Posted on May 17, 2011 at 12:56

Could be they come from the same silicon as a higher-class mcu (e.g. strm32f101r with 16kb) but have flaws that cause them to fail the requirements. If they still meet the requirements of a lower-class mcu, they could still be sold as that instead of throwing them away.

In other words: maybe you have an stm32f101r with 16kb, of which only 6kb are working properly.

If my theory is correct then it might be unwise to rely on the third timer as it might not necessarily be present in all 6kb mcus of that series.

tran
Associate II
Posted on May 17, 2011 at 12:56

I could be the reason, thank you abraxa, but i can't agree with you 100%.

does Anyone has another reason?

For detail: my STM32 is

ARM Z

STM32F101

R6T6

220OCT 93

MLT 22 744