LTC3882_15 Datasheet, PDF (67/104 Pages) Linear Technology – Dual Output PolyPhase Step-Down DC/DC Voltage Mode Controller with Digital Power System Management

LTC3882
PMBus COMMAND DETAILS (Addressing and Write Protect)
PAGE_PLUS_READ
The PAGE_PLUS_READ command provides the ability to set the page within a device, send a command and then read
the data returned by the command, all in one communication packet .
The value stored in the PAGE command is not affected by PAGE_PLUS_READ. If PAGE_PLUS_READ is used to access
data from a non-paged command, the Page Number byte is ignored.
This command uses Block Write – Block Read Process Call protocol. An example of the PAGE_PLUS_READ command
with PEC is shown in Figure 50.
NOTE: PAGE_PLUS commands cannot be nested. A PAGE_PLUS command cannot be used to read or write another
PAGE_PLUS command. If this is attempted, the LTC3882 will NACK the entire PAGE_PLUS packet and issue a CML
fault for Invalid/Unsupported Data.
1
7
11
8
1
8
1
S
SLAVE
ADDRESS
W
A
PAGE_PLUS
COMMAND CODE
A
BLOCK COUNT
(= 2)
A
8
PAGE
NUMBER
1
8
1
A
COMMAND
CODE
A…
1
7
Sr
SLAVE
ADDRESS
11
8
1
8
1
8
1
RA
BLOCK COUNT
(= 2)
A
LOWER DATA
BYTE
A
UPPER DATA
BYTE
A
Figure 50. Example of PAGE_PLUS_READ
8
PEC BYTE
11
NA P
3882 F50
WRITE_PROTECT
The WRITE_PROTECT command is used to control PMBus write access to the LTC3882.
Supported Values:
VALUE MEANING
0x80 Disable all writes except WRITE_PROTECT, PAGE, STORE_USER_ALL and MFR_EE_UNLOCK commands.
0x40 Disable all writes except WRITE_PROTECT, PAGE, STORE_USER_ALL, MFR_EE_UNLOCK, OPERATION, CLEAR_PEAKS and CLEAR_FAULTS
commands. Individual faults can also be cleared by writing a 1 to the respective status bit.
0x20 Disable all writes except WRITE_PROTECT, PAGE, STORE_USER_ ALL, MFR_EE_UNLOCK, OPERATION, CLEAR_PEAKS, CLEAR_FAULTS,
ON_OFF_CONFIG and VOUT_COMMAND commands. Individual faults can be cleared by writing a 1 to the respective status bit.
0x00 Enables writes to all commands.
The value returned by this command does not reflect the state of the WP pin, which takes precedence if not forced
low. WP pin state can be read with the MFR_COMMON command. If the WP pin is not forced low, the PAGE, OPERA-
TION, MFR_EE_UNLOCK, CLEAR_PEAKS and CLEAR_FAULTS commands are supported, and individual faults can be
cleared by writing a 1 to the respective status bit.
This command has one data byte.
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