Datasheet

LTC2977
35
2977fa
For more information www.linear.com/LTC2977
STORE_USER_ALL and RESTORE_USER_ALL
STORE_USER_ALL, RESTORE_USER_ALL commands provide access to User EEPROM space. Once a command is
stored in User EEPROM, it will be restored with an explicit restore command or when the part emerges from power-on
reset after power is applied. While either of these commands is being processed, the device will indicate it is busy, see
Response When Part Is Busy on page 67
.
STORE_USER_ALL. Issuing this command will store all operating memory commands with a corresponding EE-
PROM memory location.
RESTORE_USER_ALL. Issuing this command will restore all commands from EEPROM Memory. It is recommended
that this command not be executed while a unit is enabled since all monitoring is suspended while the EEPROM is
transferred to operating memory, and intermediate values from EEPROM may not be compatible with the values initially
stored in operating memory.
CAPABILITY
The CAPABILITY command provides a way for a host system to determine some key capabilities of the LTC2977. This
one byte command is read only.
CAPABILITY Data Contents
BITS(S) SYMBOL OPERATION
b[7] Capability_pec Hard coded to 1 indicating Packet Error Checking is supported. Reading the Mfr_config_all_pec_en bit will indicate
whether PEC is currently required.
b[6:5] Capability_scl_max Hard coded to 01b indicating the maximum supported bus speed is 400kHz.
b[4] Capability_smb_alert Hard coded to 1 indicating this device does have an ALERTB pin and does support the SMBus Alert Response
Protocol.
b[3:0] Reserved Always returns 0.
VOUT_MODE
This command is read only and specifies the mode and exponent for all commands with an L16 data format. See Data
Formats table on page 27.
VOUT_MODE Data Contents
BIT(S) SYMBOL OPERATION
b[7:5] Vout_mode_type Reports linear mode. Hard wired to 000b.
b[4:0] Vout_mode_parameter Linear mode exponent. 5-bit two’s complement integer. Hardwired to 0x13 (–13 decimal).
PMBus COMMAND DESCRIPTION