Rainbow Electronics MAX16068 - Manual (Page 14)

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MAX16068
6-Channel, Flash-Configurable System Manager
with Nonvolatile Fault Registers
ALERT
GPIO1 is configurable as the SMBus alert signal, ALERT.
ALERT asserts when any fault condition occurs. When the
SMBus host sends the ARA (Alert Response Address),
the MAX16068 responds with its slave address and
deasserts ALERT. ALERT is an open-drain output.
Set the ARAEN bit in r40h[4] to ‘1’ to disable the ARA
feature. Under these conditions, the device does not
respond to an ARA on the SMBus line.
FAULT
GPIO2 is configurable as a dedicated fault output,
FAULT. FAULT asserts when an overvoltage or under-
voltage condition occurs on the selected inputs. FAULT
dependencies are set using registers r36h and r37h
(see Table 8). When FAULT depends on more than one
MON_, the fault output asserts when one or more MON_
exceeds a programmed threshold voltage. FAULT acts
independently of the critical fault system, described in
the Critical Faults section. Use r37h[7] to set the polarity
of FAULT.
Manual Reset (MR)
GPIO3 is configurable to act as an active-low manual reset
input, MR. Drive MR low to assert RESET. RESET remains
asserted for the selected reset timeout period after MR
transitions from low to high. When connecting MR to a push-
button, use a pullup resistor. See the Reset Output section
for more information on selecting a reset timeout period.
Watchdog Input (WDI) and Output (WDO)
GPIO4 and GPIO5 are configurable as the watchdog
timer input (WDI) and output, WDO, respectively. See
Table 16 for configuration details. WDO is an open-drain,
active-low output. See the Watchdog Timer section for
more information about the operation of the watchdog
timer.
External Fault (EXTFAULT)
GPIO6 is configurable as the external fault input/output,
EXTFAULT. EXTFAULT asserts if any monitored volt-
age exceeds an overvoltage or undervoltage threshold.
EXTFAULT also asserts if a power-up or power-down
sequencing fault occurs. This signal can be used to
cascade multiple MAX16068s.
For the MAX16068, if register bit r6Dh[2] is set in addi-
tion to r72h[5], EXTFAULT going low triggers a nonvola-
tile fault log operation.
Table 8. FAULT Dependencies
REGISTER
ADDRESS
FLASH
ADDRESS
BIT RANGE DESCRIPTION
36h 236h
[0] FAULT depends on MON1 undervoltage threshold
[1] FAULT depends on MON2 undervoltage threshold
[2] FAULT depends on MON3 undervoltage threshold
[3] FAULT depends on MON4 undervoltage threshold
[4] FAULT depends on MON5 undervoltage threshold
[5] FAULT depends on MON6 undervoltage threshold
[7:6] Not used
37h 237h
[0] FAULT depends on MON1 overvoltage threshold
[1] FAULT depends on MON2 overvoltage threshold
[2] FAULT depends on MON3 overvoltage threshold
[3] FAULT depends on MON4 overvoltage threshold
[4] FAULT depends on MON5 overvoltage threshold
[5] FAULT depends on MON6 overvoltage threshold
[6] Not used
[7]
0 = FAULT is an active-low digital output
1 = FAULT is an active-high digital output