Datasheet

C515C
Data Sheet 64 2003-02
Table 14 Lock Bit Protection Types
Lock Bits at
D1, D0
Protection
Level
Protection Type
D1 D0
1 1 Level 0 The OTP lock feature is disabled. During normal
operation of the C515C-8E, the state of the EA
pin is
not latched on reset.
1 0 Level 1 During normal operation of the C515C-8E, MOVC
instructions executed from external program memory
are disabled from fetching code bytes from internal
memory. EA
is sampled and latched on reset. An OTP
memory read operation is only possible according to
ROM verification mode 2, as it is defined for a
protected ROM version of the C515C-8R. Further
programming of the OTP memory is disabled
(reprogramming security).
0 1 Level 2 Same as level 1, but also OTP memory read operation
using ROM verification mode 2 is disabled.
0 0 Level 3 Same as level 2; but additionally external code
execution by setting EA
= low during normal operation
of the C515C-8E is no more possible.
External code execution, which is initiated by an
internal program (e.g. by an internal jump instruction
above the ROM boundary), is still possible.