W78E054D Datasheet, PDF (66/89 Pages) List of Unclassifed Manufacturers – 8-bit microcontroller

W78E054D/W78E052D Data Sheet
19 CONFIG BITS
During the on-chip Flash EPROM operation mode, the Flash EPROM can be programmed and veri-
fied repeatedly. Until the code inside the Flash EPROM is confirmed OK, the code can be protected.
The protection of Flash EPROM and those operations on it are described below.
The W78E054D/W78E052D has a Special Setting Register, the config Bits, which cannot be accessed
in normal mode. The Security register can only be accessed from the Flash EPROM operation mode.
Those bits of the Security Registers cannot be changed once they have been programmed from high
to low. They can only be reset through erase-all operation. The Security Register is addressed in the
Flash EPROM operation mode by address #0FFFFh.
B7 B6 B5 B4 B3 B2 B1 B0 Config Bits
B0: Lock bit,
logic 0 : active Lock Flash
logic 1 : no Lock Flash.
B1: MOVC inhibit,
logic 0 : the MOVC instruction in external memory
cannot access the code in internal memory
logic 1 : no restriction.
B2: CBS
logic 0: Boot from LD block (0x3800).
logic 1: Boot from AP block (default).
B3: NSR ( Noise Sensitivity Reduction)
logic 0: Noise Sensitivity Reduction is enabled.
logic 1: Noise Sensitivity Reduction is disabled.
B5: Machine Cycle Select
logic 0 : 6T
logic 1 : 12T
B7: Crystal Select
logic 0 : 1/2 gain, 24MHz
logic 1 : Full gain, 40MHz
Default 1 for all security bits.
Reserved bits must be kept in logic 1.
16/8/4KB
Flash EPROM
Program Memory
0000h
3FFFh
Reserved
Security Register _FFFFh
Special Setting Register
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Publication Release Date: Jun 9, 2015
Revision A13