AN-2030: Digital Diagnostic Monitoring Interface for Optical Transceivers | F i n i s a r |
Bytes 123 – 126 contain write-only RAM for entry of a 32 bit password that allows access to user writable EEPROM at locations 128-247. The default password for Finisar devices is 0, however it can be set to any value at the factory to insure security of the user writable EEPROM contents. Please contact your Finisar sales representative for details on setting up a custom password. Once the password has been entered into locations 123 – 126, a ‘1’ should be written to address 127 (readable and writeable RAM cell). Note that the power-on default value of byte 127 is ‘0’. Once these two steps have been completed, EEPROM at locations 128 – 247 is readable and writable. The EEPROM remains readable and writable until either the password is changed or byte 127 is set to 0.
Table 3.19: Password Addresses (2-Wire Address A2h)
Byte | | Bit | Name | Description |
| | | | |
| | | | |
120-122 | | All | Reserved | Reserved |
123 | | All | Password Byte 3 | High order byte of 32 bit password |
124 | | All | Password Byte 2 | Second highest order byte of 32 bit password |
125 | | All | Password Byte 1 | Second lowest byte of 32 bit password |
126 | | All | Password Byte 0 | Low order byte of 32 bit password |
127 | | All | User EEPROM Select | ‘1’ selects user writable EEPROM at locations 128 - 247 |
Bytes 128 – 247 contain user readable/writable EEPROM that is accessed following the steps outlined above. Bytes 248 – 255 are reserved for control functions and should not be written.
Table 3.20: User EEPROM (2-Wire Address A2h)
Address | # Bytes | Name | Description |
128-247 | 120 | User EEPROM | User-writable/readable EEPROM |
| | | |
248-255 | 8 | Vendor Specific | Vendor specific control functions |
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9/26/02 Revision D | Page 27 |
