EM78P451SWM datasheet(46/54 Pages) EMC

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EM78P451S

8-Bit Microcontroller with OTP ROM

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Product Specification (V1.0) 06.01.2004

(This specification is subject to change without further notice)

Bit 9 (PTB): Protect bit.

0: Protect enabled

1: Protect disabled

Bit 8 (HLF): XTAL frequency selection.

0: Low frequency (32.768KHz)

1: High frequency

This bit is useful only when Bit 12 (MS) is 1. When MS is 0, HLF must be 0.

Bit 7 (RCT): Resistor Capacitor.

0: internal RC

1: external RC

Bit 6 (HLP): Power consumption selection.

0: Low power

1: High power

Bit 5 ~ Bit 4: DEL1 and DEL0 (SDI) input delay time options.

DEL 1

DEL 0

Delay time

0 ns

50 ns

100 ns

Bit3~0 (REN): reset pin enable bit

0: enable, P70/reset=>reset pin

1: disable, P70/reset=> P70

WORD 1 ( user’s ID code)

ID12

ID11

ID10

ID9

ID8

ID7

ID6

ID5

ID4

ID3

ID2

ID1

ID0

4.11 Instruction Set

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

or more operands. All instructions are executed within one single instruction cycle

(consisting of 2 oscillator periods), unless the program counter is changed by-

(a) Executing the instruction "MOV R2,A", "ADD R2,A", "TBL", or any other instructions

that write to R2 (e.g. "SUB R2,A", "BS R2,6", "CLR R2",

⋅⋅⋅⋅).

(b) execute CALL, RET, RETI, RETL, JMP, Conditional skip (JBS, JBC, JZ, JZA, DJZ,

DJZA) which were tested to be true.

Under these cases, the execution takes two instruction cycles.

In addition, the instruction set has the following features:

EM78P451SWM Datasheet(PDF) 46 Page - ELAN Microelectronics Corp

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