C8051F360/1/2/3/4/5/6/7/8/9
13.2.1. Summary of Flash Security Options
The level of Flash security depends on the Flash access method. The three Flash access methods that
can be restricted are reads, writes, and erases from the C2 debug interface, user firmware executing on
unlocked pages, and user firmware executing on locked pages. Table 13.1 summarizes the Flash security
features of the C8051F36x devices.
Table 13.1. Flash Security Summary
Action
C2 Debug
Interface
Permitted
Not Permitted
Permitted
Not Permitted
Permitted
Not Permitted
Permitted
Only C2DE
Not Permitted
Not Permitted
Not Permitted
User Firmware executing from:
an unlocked page
Permitted
FEDR
Permitted
FEDR
Permitted
FEDR
FEDR
FEDR
FEDR
FEDR
FEDR
a locked page
Permitted
Permitted
Permitted
Permitted
Permitted
Permitted
FEDR
FEDR
FEDR
FEDR
FEDR
Read, Write or Erase unlocked pages
(except page with Lock Byte)
Read, Write or Erase locked pages
(except page with Lock Byte)
Read or Write page containing Lock Byte
(if no pages are locked)
Read or Write page containing Lock Byte
(if any page is locked)
Read contents of Lock Byte
(if no pages are locked)
Read contents of Lock Byte
(if any page is locked)
Erase page containing Lock Byte
(if no pages are locked)
Erase page containing Lock Byte - Unlock all pages
(if any page is locked)
Lock additional pages
(change '1's to '0's in the Lock Byte)
Unlock individual pages
(change '0's to '1's in the Lock Byte)
Read, Write or Erase Reserved Area
C2DE - C2 Device Erase (Erases all Flash pages including the page containing the Lock Byte)
FEDR - Not permitted; Causes Flash Error Device Reset (FERROR bit in RSTSRC is '1' after reset)
- All prohibited operations that are performed via the C2 interface are ignored (do not cause device reset).
- Locking any Flash page also locks the page containing the Lock Byte.
- Once written to, the Lock Byte cannot be modified except by performing a C2 Device Erase.
- If user code writes to the Lock Byte, the Lock does not take effect until the next device reset.
Rev. 1.0
139
SILABS [ SILICON LABORATORIES ]
