Datasheet

3ms 3ms

1ms

GPI

GPO

UCD90124A

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SLVSAN8 –JANUARY 2012

Table 5. Rail-Status Types for Boolean Logic

Rail-Status Types

POWER_GOOD IOUT_UC_FAULT TON_MAX_FAULT_LATCH

MARGIN_EN TEMP_OT_FAULT TOFF_MAX_WARN_LATCH

MRG_LOW_nHIGH TEMP_OT_WARN IOUT_OC_FAULT_LATCH

VOUT_OV_FAULT SEQ_ON_TIMEOUT IOUT_OC_WARN_LATCH

VOUT_OV_WARN SEQ_OFF_TIMEOUT IOUT_UC_FAULT_LATCH

VOUT_UV_WARN FAN_FAULT TEMP_OT_FAULT_LATCH

VOUT_UV_FAULT SYSTEM_WATCHDOG_TIMEOUT TEMP_OT_WARN_LATCH

TON_MAX_FAULT VOUT_OV_FAULT_LATCH SEQ_ON_TIMEOUT_LATCH

TOFF_MAX_WARN VOUT_OV_WARN_LATCH SEQ_OFF_TIMEOUT_LATCH

IOUT_OC_FAULT VOUT_UV_WARN_LATCH SYSTEM_WATCHDOG_TIMEOUT_LATCH

IOUT_OC_WARN VOUT_UV_FAULT_LATCH

GPO Delays

The GPOs can be configured so that they manifest a change in logic with a delay on assertion, deassertion, both

or none. GPO behavior using delays will have different effects depending if the logic change occurs at a faster

rate than the delay. On a normal delay configuration, if the logic for a GPO changes to a state and reverts back

to previous state within the time of a delay then the GPO will not manifest the change of state on the pin. In

Figure 18 the GPO is set so that it follows the GPI with a 3ms delay at assertion and also at de-assertion. When

the GPI first changes to high logic state, the state is maintained for a time longer than the delay allowing the

GPO to follow with appropriate logic state. The same goes for when the GPI returns to its previous low logic

state. The second time that the GPI changes to a high logic state it retuns to low logic state before the delay time

expires. In this case the GPO does not change state. A delay configured in this manner serves as a glitch filter

for the GPO.

Figure 18. GPO Behavior When Not Ignoring Inputs During Delay

The Ignore Input During Delay bit allows to output a change in GPO even if it occurs for a time shorter than the

delay. This configuration setting has the GPO ignore any activity from the triggering event until the delay expires.

Figure 19 represents the two cases for when ignoring the inputs during a delay. In the case in which the logic

changes occur with more time than the delay, the GPO signal looks the same as if the input was not ignored.

Then on a GPI pulse shorter than the delay the GPO still changes state. Any pulse that occurs on the GPO when

having the Ignore Input During Delay bit set will have a width of at least the time delay.

Product Folder Link(s) :UCD90124A