i want to use the timer of 8051

[furtsiv]

hi there
i have 8051 microcontroller (ds5000fp) wich i programed my application inside external sram

i want to let it clear the content of the sram after x seconds after powering the microcontroller up
can i do it without modifying the hex i programmed inside sram ?

 

[KlausST]

Hi,

This is a confusing post.

Why do you ask about timer in the headline, but the text is talking about external Sram?

Klaus

 

[furtsiv]

using the timer to delay a command that wipe ram after x seconds
but i don't know how

 

[KlausST]

Hi,

You may use the hardware timer,
You may use a software delay loop.

Is this what you need to know?

Klaus

 

[furtsiv]

thanks but i don't know the command to do it
i only can acces its bootloader from terminal using serial

i store my program in NV RAM
i want to erase the entire ram wich is 32kb
the size of the hex is 78kb

the chip can be powered off but still remember data because of the batery attached to the mcu ,so i want the timer still counting if i remove 5v (because it can be in idle using its 3v battery)

so i want it to erase ram after x senconds but if it was in idle mode (it can't erase data) so it will erase data after next power up and timer count is superior to x
so the condition is erase data if timer count is equal or superior to x seconds