MAX16047_09 Datasheet, PDF (43/61 Pages) Maxim Integrated Products – 12-Channel/8-Channel EEPROM-Programmable System Managers with Nonvolatile Fault Registers

12-Channel/8-Channel EEPROM-Programmable
System Managers with Nonvolatile Fault Registers
Independent Watchdog Timer Operation
When r4Dh[3] is ‘1,’ the watchdog timer operates in the
independent mode. In the independent mode, the
watchdog timer operates as if it were a separate chip.
The watchdog timer is activated immediately upon V_CC
exceeding UVLO and once the boot-up sequence is
finished. If RESET is asserted by the sequencer state
machine, the watchdog timer and WDO will not be
affected.
There will be a long startup delay if r55h[6] is a ‘1.’ If
r55h[6] is a ‘0,’ there will not be a long startup delay.
In independent mode, if the Watchdog RESET Output
Enable bit r55h[7] is set to ‘1,’ when the watchdog timer
expires, WDO will be asserted then RESET will be
asserted. WDO will then be deasserted. WDO will be
low for 3 system clock cycles or approximately 1µs. If
the Watchdog RESET Output Enable bit (r55h[7]) is set
to ‘0,’ when the WDT expires, WDO will be asserted but
RESET will not be affected.
Miscellaneous
Table 24 lists several miscellaneous programmable
items. Register r5Ch provides storage space for a user-
defined configuration or firmware version number. Bit
r5Dh[0] locks and unlocks the configuration registers.
Bit r5Dh[1] locks and unlocks EEPROM addresses 00h
to 11h. The r65h[2:0] bits contain a read-only manufac-
turing revision code.
Write data to EEPROM r5Dh as normally done; howev-
er, to toggle a bit in register r5Dh, write a ‘1’ to that bit.
Table 24. Miscellaneous Settings
REGISTER/
EEPROM
ADDRESS
5Ch
5Dh
65h
BIT RANGE
DESCRIPTION
[7:0]
[0]
[1]
[7:2]
[2:0]
[7:3]
User Identification. 8 bits of memory for user-defined identification
Configuration Lock
0 = Configuration registers and EEPROM writable
1 = Configuration registers and EEPROM [except r5Dh] locked
EEPROM Fault Data Lock Flag (set automatically after fault log is triggered):
0 = EEPROM is not locked. A triggered fault log stores fault information to EEPROM.
1 = EEPROM addresses 00h to 11h are locked. Write a ‘1’ to this bit to toggle the flag.
Not used
Manufacturing revision code. This register is read only. Not stored in EEPROM.
Not used
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