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Copyright (C) 2011-2012 Reserved by Cypress Semiconductor Corporation
GX3 EEPROM Programming User Guide
2-4.
EEPROM User-defined Fields Notes
Note 1:
Node ID Settings
Every Ethernet device must have a unique MAC address. Users should always assign a
unique MAC address in the GX3 EEPROM for every GX3 based devices. Please refer to
For example, if MAC address = 00-23-45-67-89-AB, then Node ID 0 = 00h, Node ID 1 =
23h, Node ID 2 = 45h, Node ID 3 = 67h, Node ID 4 = 89h, and Node ID 5 = ABh.
Note that the Node ID value cannot be set to multicast MAC address (i.e. the 1
st
bit of MAC
address is set to “1”). If the 1
st
byte of Node ID value of EEPROM was set to “0xFF”, the
GX3 will auto-detect the programmed EEPROM as blank EEPROM
Note 2:
PID/VID/EEPROM Checksum Settings
Note the EEPROM Checksum field should be changed together with the VID/PID fields. The
value of EEPROM Checksum MUST be equal to (0xFF - SUM [EEPROM offset 03h ~ 04h]).
If SUM [EEPROM offset 03h ~ 04h] has carry, please add ‘1’ to its result. Please refer to
Note 3:
Flag - Remote Wakeup Settings
The RWU bit of EEPROM offset 05h “Flag” field is used to configure the “bmAttributes”
field of Standard Configuration Descriptor that will be reported to the USB host controller
when the GET_DESCRIPTOR command with CONFIGURATION type is issued. Please
refer the “Section 9.6.3 Configuration” of Universal Serial Bus 3.0 Spec for the detailed
description of the “bmAttributes” field of Standard Configuration Descriptor.
The USB device power mode (bus-powered or self-powered) is decided by the SELF_PWR
pin when chip powers on. This will updated to the “bmAttributes” field of Standard
Configuration Descriptor.