LAN89730 datasheet(86/218 Pages) MICROCHIP

86 / 218 page

LAN89730

DS60001348A-page 86

 2013-2015 Microchip Technology Inc.

4.7

EEPROM Controller (EPC)

The device may use an external EEPROM to store the default values for the USB descriptors and the MAC address.

The EEPROM controller supports most 256/512 byte “93C46” type EEPROMs.

The MAC address is used as the default Ethernet MAC address and is loaded into the MAC’s ADDRH and ADDRL reg-

isters. If a properly configured EEPROM is not detected, it is the responsibility of the host LAN Driver to set the IEEE

addresses.

After a system-level reset occurs, the device will load the default values from a properly configured EEPROM. The

device will not accept USB transactions from the host until this process is completed.

The EEPROM controller also allows the host system to read, write and erase the contents of the serial EEPROM.

4.7.1

EEPROM FORMAT

Table 4-56 illustrates the format in which data is stored inside of the EEPROM.

Note the EEPROM offsets are given in units of 16-bit word offsets. A length field with a value of zero indicates that the

field does not exist in the EEPROM. The device will use the field’s HW default value in this case.

Note:

A 3-wire style 2k/4k EEPROM that is organized for 256/512 x 8-bit operation must be used.

Note:

For the Device Descriptor, the only valid values for the length are 0 and 18.

Note:

For the configuration and Interface Descriptor, the only valid values for the length are 0 and 18.

Note:

The EEPROM programmer must ensure that if a String Descriptor does not exist in the EEPROM, the ref-

erencing descriptor must contain 00h for the respective string index field.

Note:

If all String Descriptor lengths are zero, then a Language ID will not be supported.

TABLE 4-56:

EEPROM FORMAT

EEPROM Address

EEPROM Contents

00h

0xA5

01h

MAC Address [7:0]

02h

MAC Address [15:8]

03h

MAC Address [23:16]

04h

MAC Address [31:24]

05h

MAC Address [39:32]

06h

MAC Address [47:40]

07h

Full-Speed Polling Interval for Interrupt Endpoint

08h

Hi-Speed Polling Interval for Interrupt Endpoint

09h

Configuration Flags

0Ah

Language ID Descriptor [7:0]

0Bh

Language ID Descriptor [15:8]

0Ch

Manufacturer ID String Descriptor Length (bytes)

0Dh

Manufacturer ID String Descriptor EEPROM Word Offset

0Eh

Product Name String Descriptor Length (bytes)

0Fh

Product Name String Descriptor EEPROM Word Offset

10h

Serial Number String Descriptor Length (bytes)

11h

Serial Number String Descriptor EEPROM Word Offset

12h

Configuration String Descriptor Length (bytes)

13h

Configuration String Descriptor Word Offset

14h

Interface String Descriptor Length (bytes)

15h

Interface String Descriptor Word Offset

LAN89730 датащи(PDF) 86 Page - Microchip Technology

LAN89730 датащи(HTML) 86 Page - Microchip Technology

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 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL