10.6 (D5h) MONITOR_CONFIG (MFR_SPECIFIC_05)

The read/write block common command configures monitor pins. They can be configured individually for one of the various types of monitoring listed in Table 28. The command format is shown in Table 29. The Monitor Type and Page byte format is shown in Table 30.

The byte position in this command determines which monitor is being configured. The size of the write command is variable. It can be up to the number of monitors supported by the given device (see Table 31). The UCD90320 NACKs the command if the size exceeds this number.

The MONITOR_CONFIG read command always returns information on all of the monitors in a given package. The number of monitors for each device is shown in Table 31.

Voltage Input monitor type is the same as Voltage monitor type, except that it is to monitor input voltage instead of output voltage. When a rail is configured as Voltage input monitor type, the threshold of POWER_GOOD_OFF and VOUT_UV_FAULT_LIMIT shall be set to the same value, otherwise the function may not function as expected. When the monitor voltage of the vin is below POWER_GOOD_OFF(VOUT_UV_FAULT_LIMIT), the function of Voltage Input monitor is to start graceful shutdown which will record Vin UV fault as the reason for shut down in NV memory with time stamp and ignore UV and UC fault log and warning for all associated rails, which is set by the Fault Slave Mask in the SEQ_CONFIG command, see 10.35.9. It is recommended using high number rail as Voltage input monitor. During the graceful shutdown period, other faults from all associated rails are still logged as normal. When the monitor voltage of the VIN is above POWER_GOOD_ON, the graceful shutdown is cancelled.

Voltage with AVS monitor type is the same as voltage monitor type, except that it supports setting the warning and fault limits by a fixed percentage of the nominal voltages.

Due to the fact that the power supply and UCD90320 may not change Vout setpoint simultaneously or with the same slew rate, UCD90320 will take the following steps to avoid false-triggering warn/fault. If the new VOUT setpoint is higher than the current VOUT setpoint, the OV warn/fault thresholds will be immediately set to their respective new levels; other thresholds will increase by 20mV step size in every 500µs until the new levels are reached. If the new VOUT setpoint is lower than the current VOUT setpoint, the UV warn/fault and Power Good On/Off thresholds will be immediately set to their respective new levels; other thresholds will decrease by 20mV step size in every 500µs until the new levels are reached.

Voltage Input with AVS monitor type is the combination of the Voltage input and Voltage with AVS monitor type.

GPI Rail is a new type rail which is defined as using a GPI pin to monitor the status. It does not have all threshold value. It has only two states: 1: asserted or non-asserted. GPI rail support ACTIVE HIGH only. When it is asserted, it is equivalent as power good. When it is de-asserted, it is equivalent as power not good and UV fault. GPI rail does not support margin function. When the Monitor Pin Index is bigger than 24, device automatically treat the page as a GPI rail. GPI rail is very similar to the VOLTAGE MONITOR type rail.

The status of the monitor pin can be read with the appropriate read command (READ_VOUT, READ_TEMPERATURE_2, READ_IOUT). The state of these monitor pins are also used to capture and report faults and warnings.

The number of monitor pins varies based on the device. UCD90320 has 24 ADC monitors and 8 GPI monitors available. Any attempt to use a monitor number that is not available on a given device (denoted by “Error” in the table) results in a NACK to the MONITOR_CONFIG write command.