EM78P447SAP datasheet(27/55 Pages) EMC

27 / 55 page

EM78P447S

OTP ROM

4.8 CODE Option Register

The EM78P447S has one CODE option word that is not a part of the normal program memory. The option bits cannot

be accessed during normal program execution.

Bit12

Bit11

Bit10

Bit9

Bit8

Bit7

Bit6

Bit5 Bit4 Bit3 Bit2 Bit1

Bit0

/ENWDT

CLK

HLP

TYPE

• Bit 12 (MS):Oscillator type selection.

0: RC type

1: XTAL type(XTAL1 and XTAL2)

• Bit 11 (/ENWDT): Watchdog timer enable bit.

0: Enable

1: Disable

• Bit 10 (CLK): Instruction period option bit.

0: two oscillator periods.

1: four oscillator periods.

Refer to the section on Instruction Set.

• Bit 9 (CS): Code Security Bit

0: Security On

1: Security Off

• Bit 8 (HLF): XTAL frequency selection

0: XTAL2 type (low frequency, 32.768KHz)

1: XTAL1 type (high frequency)

This bit will affect system oscillation only when Bit12(MS) is “1”. When MS is”0”, HLF must be “0”.

<Note>: The transient point of system frequency between HXT and LXY is around 400 KHz.

• Bit 7 (HLP): Power selection.

0: Low power

1: High power

• Bit 6(TYPE): Type selection for EM78P447SA or B.

0: EM78P447SB

1: EM78P447SA

• Bit 5 and Bit4: Reserved.

The bit5 set to “1” all the time.

The bit4 set to “0” all the time.

• Bit 3~0 : Customer’s ID code

This specification is subject to change without prior notice.

06.25.2003 (V1.1)

EM78P447SAP 数据表(PDF) 27 Page - ELAN Microelectronics Corp

EM78P447SAP 数据表(HTML) 27 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

数据表下载