EM78P468NBQSSLASHNBQJ datasheet(52/82 Pages) EMC

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EM78P468N/L

8-Bit Microcontroller

•

Product Specification (V1.6) 12.31.2007

(This specification is subject to change without further notice)

Bit 3 (HLP):

Power consumption selection. If the system usually runs in green mode, it

must be set to low power consumption to help support the energy saving issue. It is

recommended that low power consumption mode is selected.

HLP = “0”:

Low power consumption mode

HLP = “1”:

High power consumption mode

Bits 2~0 (PR2~PR0):

Protect Bit

PR2~PR0 are protection bits. Each protect status is as follows:

PR2

PR1

PR0

Protect

Enable

Disable

6.12 Instruction Set

Each instruction in the instruction set is a 13-bit word divided into an OP code and one

or more operands. Normally, all instructions are executed within one single instruction

cycle (one instruction consists of 2 oscillator periods), unless the program counter is

changed by instruction "MOV R2,A", "ADD R2,A", or by instructions of arithmetic or

logic operation on R2 (e.g. "SUB R2,A", "BS(C) R2,6", "CLR R2",

⋅⋅⋅⋅). In this case, the

execution takes two instruction cycles.

If for some reasons, the specification of the instruction cycle is not suitable for certain

applications, try modifying the instruction as follows:

Execute within two instruction cycles the "JMP", "CALL", "RET", "RETL", & "RETI"

instructions, or the conditional skip instructions ("JBS", "JBC", "JZ", "JZA", "DJZ",

"DJZA") which were tested to be true. Also execute within two instruction cycles the

instructions that are written to the program counter.

Additionally, the instruction set offers the following features:

(1) Every bit of any register can be set, cleared, or tested directly.

(2) The I/O register can be regarded as general register. That is, the same instruction

can operate on I/O register.

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