Datasheet

LTC2977
66
2977fa
For more information www.linear.com/LTC2977
PMBus COMMAND DESCRIPTION
MFR_EE_ERASE
The MFR_EE_ERASE command is used to erase the entire contents of the user EEPROM space and configures this
space to accept new program data. Writing values other than 0x2B will lock the part. Reads return the last value written.
MFR_EE_ERASE Data contents
BIT(S) SYMBOL OPERATION
b[7:0] Mfr_ee_erase[7:0] To erase the user EEPROM space and configure to accept new data:
1) Use the appropriate Mfr_ee_unlock sequence to configure for Mfr_ee_erase commands with or without PEC.
2) Write 0x2B to Mfr_ee_erase.
The part will indicate it is busy erasing the EEPROM by the mechanism detailed below.
MFR_EE_DATA
The MFR_EE_DATA command allows the user to transfer data directly to or from the EEPROM without affecting RAM
space.
To read the user EEPROM space issue the appropriate Mfr_ee_unlock command and perform Mfr_ee_data reads until
the EEPROM has been completely read. Extra reads will lock the part and return zero. The first read returns the 16-bit
EEPROM packing revision ID that is stored in ROM. The second read returns the number of 16-bit words available;
this is the number of reads or writes to access all memory locations. Subsequent reads return EEPROM data starting
with the lowest address.
To write to the user EEPROM space issue, the appropriate Mfr_ee_unlock and Mfr_ee_erase commands followed by
successive Mfr_ee_data word writes until the EEPROM
is full. Extra writes will lock the part. The first write is to the
lowest address.
Mfr_ee_data reads and writes must not be mixed.
MFR_EE_DATA Data Contents
BIT(S) SYMBOL OPERATION
b[7:0] Mfr_ee_data[7:0] To read user space
1) Use the appropriate Mfr_ee_unlock sequence to configure for Mfr_ee_data commands with or without PEC.
2) Read Mfr_ee_data[0] = PackingId (MFR Specific ID).
3) Read Mfr_ee_data[1] = NumberOfUserWords (total number of 16-bit word available).
4) Read Mfr_ee_data[2] through Mfr_ee_data[NumberOfUserWords+1] (User EEPROM data contents)
To write user space
1) Initialize the user memory using the sequence described for the MFR_EE_ERASE command.
2) Use the appropriate Mfr_ee_unlock sequence to configure for Mfr_ee_data commands with or without PEC.
3) Write Mfr_ee_data[0] through Mfr_ee_data[NumberOfUserWords-1] (User EEPROM data content to be written)
The part will indicate it is busy erasing the EEPROM by the mechanism detailed below.