ADM1168 Analog Devices, ADM1168 Datasheet - Page 15

• Manufacturer Part Number: ADM1168
• Description: Super Sequencer and Monitor with Nonvolatile Fault Recording
• Manufacturer: Analog Devices

Specifications of ADM1168

• # Supplies Monitored: 8
• Volt Monitoring Accuracy: 1%
• # Output Drivers: 8
• Fet Drive/enable Output: Both
• Package: 32 ld LQFP

SEQUENCING ENGINE
OVERVIEW
The ADM1168 SE provides the user with powerful and flexible
control of sequencing. The SE implements a state machine control
of the PDO outputs with state changes conditional on input
events. SE programs can enable complex control of boards such
as power-up and power-down sequence control, fault event
handling, and interrupt generation on warnings. A watchdog
function that verifies the continued operation of a processor
clock can be integrated into the SE program. The SE can also be
controlled via the SMBus, giving software or firmware control
of the board sequencing.
The SE state machine comprises 63 state cells. Each state has the
following attributes:
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Table 7. Sample Sequence State Entries
State
IDLE1
IDLE2
EN3V3
DIS3V3
EN2V5
DIS2V5
FSEL1
FSEL2
PWRGD
It monitors signals indicating the status of the eight input
pins, VP1 to VP3, VH, and VX1 to VX4.
It can be entered from any other state.
Three exit routes move the state machine onto a next state:
sequence detection, fault monitoring, and timeout.
Delay timers for the sequence and timeout blocks can be
programmed independently and changed with each state
change. The range of timeouts is from 0 ms to 400 ms.
The output condition of the eight PDO pins is defined and
fixed within a state.
It can transition from one state to the next in less than
20 μs, which is the time needed to download a state
definition from EEPROM to the SE.
Sequence
If VX1 is low, go to State IDLE2.
If VP1 is okay, go to State EN3V3.
If VP2 is okay, go to State EN2V5.
If VX1 is high, go to State IDLE1.
If VP3 is okay, go to State PWRGD.
If VX1 is high, go to State IDLE1.
If VP3 is not okay, go to State DIS2V5.
If VP2 is not okay, go to State DIS3V3.
If VX1 is high, go to State DIS2V5.
Timeout
If VP2 is not okay after 10 ms,
go to State DIS3V3.
If VP3 is not okay after 20 ms,
go to State DIS2V5.
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The ADM1168 offers up to 63 state definitions. The signals
monitored to indicate the status of the input pins are the
outputs of the SFDs.
WARNINGS
The SE also monitors warnings. These warnings can be generated
when the ADC readings violate their limit register value or
when the secondary voltage monitors on VPx and VH are
triggered. The warnings are OR’ e d together and are available
as a single warning input to each of the three blocks that enable
exiting a state.
SMBus JUMP (UNCONDITIONAL JUMP)
The SE can be forced to advance to the next state unconditionally.
This enables the user to force the SE to advance. Examples of the
use of this feature include moving to a margining state or debugging
a sequence. The SMBus jump or go-to command can be seen as
another input to sequence and timeout blocks to provide an exit
from each state.
It can trigger a write of the black box fault and status
registers into the black box section of EEPROM.
Monitor
If VP1 is not okay, go to State IDLE1.
If VP1 or VP2 is not okay, go to State FSEL2.
If VP1 or VP2 is not okay, go to State FSEL2.
If VP1 is not okay, go to State IDLE1.
If VP1, VP2, or VP3 is not okay, go to State FSEL1.
MONITOR
FAULT
Figure 19. State Cell
STATE
SEQUENCE
TIMEOUT
ADM1168