JAJSMF5B september 2022 – june 2023 TPS25990
PRODUCTION DATA
OT_WARN is a standard PMBus® command for configuring or reading an 8-bit threshold for the device overtemperature warning detection. This command uses the PMBus® DIRECT format. When reading and writing to this register, use the coefficients shown in Table 8-67, Equation 19, and Equation 20 to convert between the real world units and hexadecimal values.
This command uses the PMBus® read or write word protocol.
Contents of this register are compared to the VTEMP ADC telemetry value. If the device temperature rises above the value in this register, the OT_WARN flags are set in the respective registers. The SMBA# signal is asserted. When the device temperature falls below the OT_WARN threshold, and the CLEAR_FAULTS command is sent afterwards, this warning flag and alert are cleared.
| Bit | Name | Description | Minimum Value | Maximum Value | Default Value | Access |
|---|---|---|---|---|---|---|
15:0 | OT_WARN | Device overtemperature warning threshold | 0x0000h (-229 ºC) | 0x00FFh (500 ºC) | 0x007Eh (131 ºC) | Read/Write |
When an overtemperature warning is detected, the device:
sets the STATUS_TEMP bit in the STATUS_BYTE register
sets the OT_WARN bit in the STATUS_TEMP register
fills-up one of the Blackbox RAM registers (if available to write) writing the event identifier as OT_WARN and relative time stamp information
increases the Blackbox RAM address pointer in the BB_TIMER register by one (1) if it was previously less than six (6), otherwise resets to zero (0). This change in the address pointer only occurs if one of the Blackbox RAM registers is available to write
notifies the host by asserting SMBA#, if it is not masked setting the STATUS_TEMP bit in the ALERT_MASK register and the GPIO4 pin is configured as SMBA# Output in the GPIO_CONFIG_34 register
A write command to this register should be preceded by the MFR_WRITE_PROTECT command to unlock the device first to prevent accidental accidental/spurious writes.