Status of AT89S52 after reset??

[Suresh R]

I would like to know the status of RAM, FLASH and SFR after a Reset is applied to the reset pin of AT89S52.

What i know on this is.,
RAM contents would not be changed.
Program counter starts again from 0000H of FLASH memory.
But not clear with SFR's

Can i get some information on this?

 

[IanP]

Refer to the attached table (from 89S52 data sheet), where X =don't care ..

Regards,
IanP

 

[Suresh R]

Thank you.
i will be reseting the AT 89S52 for every one second.
In this case, would it be safe to store the data in its internal RAM before reset occurs and retrive it after the reset and work on it??

 

[IanP]

Write a short code and check it out .. should work ..

The internal reset algorithm writes 0s to all the SFRs except the port latches, the Stack Pointer, and SBUF. The port latches are initialized to FFH, the Stack Pointer to 07H, and SBUF is indeterminate. Table 1 lists the SFR reset values. The internal RAM is not affected by reset. On power up the RAM content is indeterminate.

**broken link removed**
Regards,
IanP

 

[Suresh R]

Write a short code and check it out .. should work ..

The internal reset algorithm writes 0s to all the SFRs except the port latches, the Stack Pointer, and SBUF. The port latches are initialized to FFH, the Stack Pointer to 07H, and SBUF is indeterminate. Table 1 lists the SFR reset values. The internal RAM is not affected by reset. On power up the RAM content is indeterminate.

**broken link removed**
Regards,
IanP

Thank you. i would do it.