OX16CF950 datasheet(46/60 Pages) ETC

46 / 60 page

Page 46

OXCF950 DATA SHEET V1.1

OXFORD SEMICONDUCTOR LTD.

7 SERIALEEPROM SPECIFICATION

The OXCF950 can be configured using an optional serial

electrically-erasable programmable read only memory

(EEPROM). If the EEPROM is not present, the device will

remain in its default configuration after reset. Although this

may be adequate for some applications, many will benefit

from the degree of programmability afforded by this

feature. The EEPROM also allows accesses to the

integrated UART, which can be useful for default setups.

The EEPROM interface supports a variety of serial

EEPROM devices that have a proprietary serial interface

known as MicrowireTM. This interface has four pins which

supply the memory device with a clock, a chip-select, and

serial data input and output lines. In order to read from

such a device, a controller has to output serially a read

command and address, then input serially the data. The

interface controller has been designed to handle (auto

detect) the following list of compatible devices that have a

16-bit data word format but differ in memory size (and

hence the number of address bits). NM93C46 (64

WORDS), NM93C56 (128 WORDS), devices with 256

WORDS, 512 WORDs and 1024 WORDS.

The OXCF950 incorporates a controller module which

reads data from the serial EEPROM and writes data into

the relevant register space. It performs this operation in a

sequence which starts immediately after a CF/PCMCIA

reset and ends either when the controller finds no

EEPROM is present or when it reaches the end of the

eeprom data.

Following device configuration, driver software can access

the serial EEPROM through four bits in the device -specific

Local Configuration Register ESC[4:1]. Software can use

this register to manipulate the device pins in order to read

and modify the EEPROM contents as desired.

A Windows® based utility to program the EEPROM is

available. For further details please contact your local

distributor.

MicrowireTM is a trade mark of National Semiconductor. For

a description of MicrowireTM, please refer to National

Semiconductor data manuals.

7.1

EEPROM data Organisation

The serial EEPROM data is divided into 4 zones. The size

of each zone is an exact multiple of 16-bit WORDs. Zone 0

is allocated to the header. An EEPROM program must

contain a valid header before any further data is

interrogated. The EEPROM can be programmed from the

CF/PCMCIA Interface.. The general EEPROM data

structure is shown in Table 5.

DATA Zone

Size (WORDS)

Description

One

Header

Two or more

CIS Configuration

One or more

Local Configuration registers

Multiples of two

Function Access

Table 38: EEPROM Data Format

7.2

Zone 0 : Header

The zone header identifies the EEPROM program as valid, and is the first value to be read and is at address 0 in the EEPROM.

It has the following format:

OX16CF950 датащи(PDF) 46 Page - List of Unclassifed Manufacturers

OX16CF950 датащи(HTML) 46 Page - List of Unclassifed Manufacturers

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

датащи скачать

ссылки URL