Serial Flash Protected Area


Is there any reason why the SPI flash chips always have the protected area in the upper addresses at the end of the available memory?

All of the CPUs that I know start booting from the SPI flash by reading some information which begins at the address 0. So if the beginning of the flash gets corrupt, then the CPU is dead and we can't reprogram the flash by software. Therefore it seems logical to protect the beginning of the flash, not the end.

But why the protection is always done in the opposite way? Is there any logical reason for that?

Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com
.

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