ADM1062ASU datasheet(19/32 Pages) AD

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Preliminary Technical Data

ADM1062

Rev. PrJ | Page 19 of 32

ADM1062 SEQUENCING ENGINE

The ADM1062 incorporates a Sequencing Engine (SE) which

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

powerup and power down sequence control, fault event

handling, interrupt generation on warnings etc. A watchdog

function, to verify 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

Considering the function of the SE from an applications

viewpoint it is most instructive to think of the SE as providing a

“state” for a state machine. This state has the following

attributes:

• it is used to monitor signals indicating the status of the 10

input pins, VP1-4, VH and VX1-VX5

• it can be entered from any other state

• there are three exit routes which move the state machine on

to a “next state”, these are:

End of Step detection

Monitoring fault

Timeout

• delay timers for the End of Step and Timeout blocks above

can be programmed independently and will change with each

state change. The range of timeouts is from 0ms to 400ms

• the output condition of the 10 PDO pins is defined and fixed

within a state

• the transition from one state to the next is made in less than

20µs. This is the time taken to download a state definition

from EEPROM to the SE.

Figure 27. State Cell

The ADM1062 offers up to 63 such state definitions. The signals

being monitored to indicate the status of the input pins are the

outputs of the SFD’s.

WARNINGS

The SE is also monitoring the Warnings. These are generated by

ADC readings violating their limit register value or by the

secondary voltage monitors on VP1-4, VH. These are all OR’ed

together and available as a single “Warnings” input to each of

the three blocks which enable exiting from a state.

SW FLOW-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 where this might be used include moving to

a margining state or as a method of debugging a sequence. The

SW Flow or Go to command can be seen as another input to

End of Step and Timeout blocks which provide an exit from

each state.

Table 6. Example Sequence States Entries

State

End of Step

Timeout

Monitor

IDLE1

If VX1 is LOW then go to State IDLE2

IDLE2

If VP1 is OK then go to State EN3V3

EN3V3

If VP2 is OK then go to State EN2V5

If VP2 is NOT OK after 10ms then

goto State DIS3V3

If VP1 is NOT OK then goto State IDLE1

DIS3V3

If VX1 is HIGH then go to State IDLE1

EN2V5

If VP3 is OK then go to State PWRGD

If VP3 is NOT OK after 20ms then

goto State DIS2V5

If VP1 OR VP2 is NOT OK then goto State

FSEL2

DIS2V5

If VX1 is HIGH the go to State IDLE1

FSEL1

If VP3 is NOT OK then go to State

DIS2V5

If VP1 OR VP2 is NOT OK then goto State

FSEL2

If VP2 is NOT OK then go to State

DIS3V3

If VP1 is NOT OK then goto State IDLE1

PWRGD

If VX1 is HIGH then go to State DIS2V5

If VP1 OR VP2 OR VP3 is NOT OK then goto

State FSEL1

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