MPC5777C C55FMC Flash erase suspend

[manaswini1317]

Hi,

I am planning to erase the large blocks(6MB) and during erase, I would want to suspend the erase and flash data. Before, flashing the data, I would like to check if the block I am flashing to has been erased or not . I could not find any Hardware bit to indicate if a specific block has been erased or not in the MCR register of C55FMC module. Kindly help me figure out this observation.

Regards

Manaswini

[lukaszadrapa]

Hi,

information about the blocks which are being erased during erase suspend operation can be found in C55FMC_SEL0-3 registers. These blocks can't be programmed during erase suspend, of course.

If you are interested in blocks which were erased earlier then there's no such information in registers. It's up to user to perform blank check (read the flash if it contains all 0xFF).

Regards,

Lukas

[manaswini1317]

Hi Lukas,

Thanks for your quick response. I am interested to know status of a block whether or not it has been erased before I set the erase suspend bit to HIGH.

The flow is something like this,

initiate erase for 6MB -> Suspend erase ->Check if desired block is erased or not -> if yes, flash data to that block

[lukaszadrapa]

There's no such information. Solution is to erase the blocks one by one (do not start erase operation for all required blocks by one command), so you know exactly which ones are already erased.

Regards,

Lukas

[manaswini1317]

Got it. If I plan to erase 4MB i.e FFFF0000 and try to erasing the blocks, would the bits in SEL0-3 register reset once that specific block gets erased. say suppose 16th block is erased, does the SEL2 register clear the 16th bit.

[lukaszadrapa]

No, SELn registers are not updated by the flash controller.

Regards,

Lukas

[manaswini1317]

Thanks Lukas.