EM78459AM datasheet(55/62 Pages) EMC

55 / 62 page

EM78458/459

8-Bit Microcontroller with MASK ROM

Product Specification (V1.4) 05.27.2005

• 49

(This specification is subject to change without further notice)

4.14 CODE OPTION

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

ENWDTB

CK2

HLF

RCT

Bit 0:

Reserved..

The bit0 set to ”0” all the time.

Bit 1 (RCT):

RC type.

0: Internal C, External R

1: External RC

Bit 2 (HLF):

Frequency mode.

0: Low frequency(<32.768KHz)

1: High frequency(

≥32.768KHz)

Bit 3 (MS):

Oscillator types.

0: RC type

1: Crystal type

Bit 4 (CK2):

Clocks per instruction.

0: 2 clocks

1: 4 clocks

Bit 5 (ENWDTB):

WatchDog Timer (WDT) control.

0: Enable WDT

1: Always disable WDT

4.15 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.

In addition, the instruction set has the following features:

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

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

instruction can operate on I/O registers.

EM78459AM Datasheet(PDF) 55 Page - ELAN Microelectronics Corp

EM78459AM Datasheet(HTML) 55 Page - ELAN Microelectronics Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62

Datasheet Download

Link URL