Parallel Programming Interface; Security Function - Cypress FR81S CY91F52 Series Recommendation For Hardware Setup

5.4

Parallel programming interface

In case of using Flash security and unknown key or if the OCD interface function is disabled, the Flash may be erased
only by the parallel programming mode. The parallel programming is supported by GALEP-5D:
Further information about GALEP-5D can be found on the web page:
http://www.conitec.net/english/galep5d.php
5.5

Security function

This MCU series has a security function to impede improper access to the internal flash. To enable this function, the
user has to write in a specific flash memory location a password and a flash security code. From then security is turned
on and access restrictions are imposed on subsequent accesses to flash memory.
Once security has been turned on, the security is not turned off unless the entire flash memory area is erased (using
serial or parallel programming method).
To avoid not authorized access to memory during debugging the user is forced to enter the same password previously
written in flash memory. Once authentication by password of on-chip debugger (OCD) is completed, you can read the
content of flash memory from external by using OCD.
The debug security area is allocated at 30 bytes of built-in flash start address +4 to +33. (For further information please
go to the Hardware Manual of this series)
www.cypress.com
Figure 36. Parallel programming with GALEP-5D
Document No. 002-09375 Rev. *B
Recommendation for Hardware Setup 32-Bit FR81S Family
29