Analog Devices LT7170 Reference Manual page 11

Reference Manual
PMBUS COMMAND DETAILS
ZONE_CONFIG
The ZONE_CONFIG command is used to assign the currently selected channel to a specific zone number for ZONE_WRITE operations. Zone
configuration only needs to be performed once, but zone numbers can be changed at any time.
The zone of the channel can be assigned to any zone number between 0x00 and 0x7F. It can also be set to 0xFE, which means no zone. Any
channel programmed to no zone ignores ZONE_WRITE operations.
The ZONE_CONFIG command uses the SMBus word write and word read protocols.
Table 4. ZONE_CONFIG Bits and Meaning
Bits Meaning
[15:8] Must be 0xFE
[7:0] Assigned zone
ZONE_ACTIVE
The ZONE_ACTIVE command sets the active zone for ZONE_WRITE operations. When ZONE_WRITE is sent by the bus controller, the active
zone controls which channels are affected by that write.
The active zone can be set to any zone number between 0x00 and 0x7F. The active zone can also be set to 0xFF, which means all zone. If a
ZONE_WRITE is sent while the active zone is set to all zone, any channel not programmed to no zone via ZONE_CONFIG is affected by that
write.
The ZONE_ACTIVE command must be sent using the ZONE_WRITE address (0x37) as a ZONE_WRITE operation. If the ZONE_ACTIVE
command is sent to the global, device, or rail addresses, the invalid command bit is set in STATUS_CML.
Table 5. ZONE_ACTIVE Bits and Meaning
Bits Meaning
[15:8] Must be 0xFE
[7:0] Active zone
WRITE_PROTECT
The WRITE_PROTECT command is used to control writing to the LT7170/LT7170-1. When WRITE_PROTECT is set to 0x00, writes to all
commands are enabled.
The PAGE_PLUS_WRITE command can be used to write any command that is not write protected. The PAGE_PLUS_READ command can be
used to read any command.
Table 6. WRITE_PROTECT Byte and Meaning
Byte Meaning
0x80 Disable all writes except to the WRITE_PROTECT, PAGE, MFR_NVM_UNLOCK, and STORE_USER_ALL commands.
0x40 Disable all writes except to the WRITE_PROTECT, PAGE, MFR_NVM_UNLOCK, MFR_CLEAR_PEAKS, STORE_USER_ALL, OPERATION, and
CLEAR_FAULTS commands. Individual fault bits can be cleared by writing a 1 to the respective bits in the STATUS registers.
0x20 Disable all writes except to the WRITE_PROTECT, OPERATION, MFR_NVM_UNLOCK, MFR_CLEAR_PEAKS, CLEAR_FAULTS, PAGE, ON_OFF_CONFIG,
VOUT_COMMAND, and STORE_USER_ALL commands. Individual fault bits can be cleared by writing a 1 to the respective bits in the STATUS registers.
0x10 Reserved, must be 0.
0x08 Reserved, must be 0.
0x04 Reserved, must be 0.
0x02 Reserved, must be 0.
0x01 Reserved, must be 0.
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