8-bit Microcontrollers中的主题 Re: MC9S08DZ32 - local variable allocation causing reset problem

MC9S08DZ32 - local variable allocation causing reset problem

mroczeks — Thu, 29 Oct 2020 09:30:03 GMT

Hi All,

While working with MC9S08DZ32 unit I found some strange issue.

Have a look at the function causing the problem:

U8 eepromSaveAll(EEPROM_DATA_BLOCK * paramBlock,EEPROM_TAddress epp_address){     U8 status;     U8 i = 0;     U8 size = sizeof(EEPROM_DATA_BLOCK);     byte Array[sizeof(EEPROM_DATA_BLOCK)];     (void)memcpy(Array,paramBlock,sizeof(EEPROM_DATA_BLOCK));     while(size)     {         status = EEPROM_SetByte(epp_address++,Array[i]);         size--;         i++;     }     return status;

It is causing heavy instability of the system. Every call or every second call causes device reset.

Interesting thing is that when Array array is declared with static the problem disappears:

static byte Array[sizeof(EEPROM_DATA_BLOCK)];

I have had no time to investigate that more deeply. Problem is solved but curosity remains

Any ideas?

Re: MC9S08DZ32 - local variable allocation causing reset problem

kef — Mon, 31 Jan 2011 19:43:54 GMT

How big is EEPROM_DATA_BLOCK and how big is your stack? Nonstatic Array is allocated on stack...

Re: MC9S08DZ32 - local variable allocation causing reset problem

mroczeks — Tue, 01 Feb 2011 21:18:23 GMT

EEPROM_DATA_BLOCK is 42 bytes. Stack is 128 bytes. There's a lot code inside so probably stack is overflown. I will have a look at it later but it seems to be clear for me now.

Thanks!

Re: MC9S08DZ32 - local variable allocation causing reset problem

mroczeks — Tue, 08 Nov 2011 18:32:33 GMT

Problem solved. Stack overflow...