MC56F82xxx How to protect flash from unwanted readings ? (through JTAG)

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

MC56F82xxx How to protect flash from unwanted readings ? (through JTAG)

722 Views
antonio66
Contributor III

Hi,

for the initialization of the MC56F82xxx i'm using the QuickStart configuration tool from freescale.

I program the device with the CW10.6 with the "RUN" option. The program and the verify of the flash it's ok. The program run Ok.

I need at the end of the verify to protect the program from unwanted read through JTAG.

In the quick start window (in the picture):

18675_18675.pngpastedImage_0.png

I do not konw who is the master0 ...master 3 and also i do not know how to program the FMC_PFAPR at the end of the programming.

I Should program it at the start of the firmware?

 

Somebody have some suggestions ?

 

best regards

Labels (1)
2 Replies

522 Views
johnlwinters
NXP Employee
NXP Employee

The flash control block is located in the first block of flash, the block that begins at zero.

If this block is errased (becomes all ones), and the device reset, it will lock.

This is not how security is normally set, but how some users fall into it unexpectedly.

Normally, when security is desired, the flash control block is written to such that the flash is secured at the next reset, using the normal flash writing methods illustrated by the sample programs.

There is no "JTAG" specific way to do this, other than writing to the flash.  This can be accomplished with JTAG, or with the internal processor core.

There is no option on the debug (nor run) configurations to lock the flash after loading.

This can be built into the program image, or modified later to lock the flash only after the program runs.


522 Views
antonio66
Contributor III

Hi Jhon,

Thankyou for your answer.

On Quick start, in the page "FMC flash memory controller" (picture up) I do not konw who is the master0 ...master 3. Do you konw something?

By

Antonio

0 Kudos