W78E054D Datasheet, PDF (67/89 Pages) List of Unclassifed Manufacturers – 8-bit microcontroller

W78E054D/W78E052D Data Sheet
Bit 0: Lock bits
0: Lock enable
1: Lock disable
This bit is used to protect the customer's program code in the W78E054D/W78E052D. It may be set
after the programmer finishes the programming and verifies sequence. Once these bits are set to logic
0, both the FLASH data and Special Setting Registers cannot be accessed again.
Bit 1: MOVC inhibit
0: MOVC inhibit enable
1: MOVC inhibit disable
This bit is used to restrict the accessible region of the MOVC instruction. It can prevent the MOVC in-
struction in external program memory from reading the internal program code. When this bit is set to
logic 0, a MOVC instruction in external program memory space will be able to access code only in the
external memory, not in the internal memory. A MOVC instruction in internal program memory space
will always be able to access the ROM data in both internal and external memory. If this bit is logic 1,
there are no restrictions on the MOVC instruction.
Bit 2: CBS
Config boot select at Power-on reset and external reset.
CBS=1: Boot from APROM block (default).
CBS=0: Boot from LDROM block (0x3800).
Bit 3: NSR (Noise Sensitivity Reduction)
NSR=1: Noise Sensitivity Reduction is disabled.
NSR=0: Noise Sensitivity Reduction is enabled.
Bit 4: Must be “1”
Bit 5: Machine Cycle Select
This bit is select MCU core, default value is logic 1, and the MCU core is 12T per instruction. Once this
bit is set to logic 0, the MCU core is 6T per instruction.
Bit 6: Must be “1”
Bit 7: Crystal Select
0 (24MHz): If system clock is slower than 24MHz, programming “0”. It can reduce EMI effect and save
the power consumption.
1 (40MHz): If system clock is faster than 24MHz, programming “1”.
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Publication Release Date: Jun 9, 2015
Revision A13