Forums

using flash for data storage (as EEPROM)

Posted by Pallavaggarwal

on Dec 25 2006 11:19 AM

How to read flash?nothing found on reading either on datasheet nor on device driver pdf
FMA is 32bit register but has only 15bits(0-14 and writable) so in LMS811 64k memory access how to write the address..... ?

if i have programed a word on alocation and if want to reprogramm that location with different data whether i have erase that block first to reprogramm?

Please help as soon as possible
thanks and regards
pallav aggarwal

Posted by TI - Eric Hewing

on Dec 27 2006 10:13 AM

Expert4160 points

I have replied to the support request you created.

For anyone else wondering, you can read any flash location just as you read SRAM or any other memory mapped area.

You can also use the FMA register to look at the contents of the flash. There are only 15 bits because 64k represents addresses 0-0xFFFF.

Posted by Pallavaggarwal

on Dec 27 2006 10:54 AM

Prodigy130 points

thanks for you reply
to represent 0xFFFF address i think we need 16bits and not 15bits please correct me if i am wrong.

also please tell me how to access flash memory
tell me if i want to read memory location 0x0000FC00

also tell me if we have to erase the block every time if we want to reprogram some bytes stored..

Again thankyou very much

Pallav Aggarwal

Posted by TI - Eric Hewing

on Dec 27 2006 11:15 AM

Expert4160 points

Oops, you're correct - we do need 16 bits. It's been a long 3 day vacation :)

Looking at the documentation, the FMA does have 16 bits to represent the address offset, so I don't see where you're getting the 15 bits from. Try downloading the latest datasheet.

To read any memory, the following will work (this is the HWREG macro in DriverLib):

data = (*((volatile unsigned long *)(x))), where x is the address you want to read.

Posted by Pallavaggarwal

on Dec 27 2006 11:19 AM

Prodigy130 points

thanks a lot let me check if this solves my prob i will tell u soon..

Thanks and Regards
Pallav Aggarwal

Posted by Pallavaggarwal

on Dec 27 2006 11:35 AM

Prodigy130 points

hey dear u please see in datasheet..101 page in FMA...16bit is white but written RO(readonly i think)...
this is what is latest on website.i downloaded right now.

i had older that has 16thbit in orange and RO written too....please help what the hell it is?

Reagards
Pallav Aggarwal

Posted by TI - Eric Hewing

on Dec 27 2006 11:40 AM

Expert4160 points

It should be R/W. It's a typo.

Posted by Pallavaggarwal

on Dec 27 2006 11:42 AM

Prodigy130 points

thanks for nice help

Posted by Pallavaggarwal

on Dec 28 2006 03:47 AM

Prodigy130 points

Solved my problem thanks
is there any way to program few bytes at the time of programming flash....suppose i have to programm a new code to chip but the datastorage flash space(i have use 0x0000fc00-8bytes) will be eraased so is there any way to programm this portion while downloading the progamm to chip..

Thanks & Regards
Pallav Aggarwal

Posted by igorp

on Dec 28 2006 15:25 PM

Intellectual370 points

Never the less there is an arror in documentation. The datasheet of LM3S811 says in page 37, Table 3-1 (mine is from October, 8) that on-chip flash is from 0x0000 to 0x 7FFF.

Regards

Igor