ZHCSG68F MARCH 2017 – JANUARY 2019 TPSM846C23
PRODUCTION DATA.
The OT_WARN_LIMIT command sets the value of the temperature, in degrees Celsius, that causes an overtemperature warning condition, when the sensed temperature from the internal sensor exceeds this limit. Upon triggering the overtemperature warning, the device takes the following actions:
Once the overtemperature warning is tripped, the warning flag is latched until the internal sensed temperature decreases 20°C from the OT_WARN_LIMIT.
The OT_WARN_LIMIT must always be less than the OT_FAULT_LIMIT. Writing a value to OT_WARN_LIMIT greater than or equal to OT_FAULT_LIMIT causes the device to set the CML bit in the STATUS_BYTE and the invalid data (ivd) bit in the STATUS_CML registers as well as assert the SMBALERT signal. In such case, the register content will remain unchanged. This behavior can be overridden by the user setting Data Limit Override (DLO) in MFR_SPECIFIC_21[4].
The default OT_WARN_LIMIT is mathematically derived from the EEPROM backed OTF limit by subtracting 25 from (4Fh) OT_FAULT_LIMIT to reach the default OT_WARN_LIMIT. If the calculated OTW is less than 100°C, then the default value is set to 100°C. OTW=max(OTF-25, 100)
The OT_WARN_LIMIT takes a two byte data word formatted as shown below:
| COMMAND | OT_WARN_LIMIT | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Format | Unsigned binary | |||||||||||||||
| Bit Position | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Access | r | r | r | r | r | r | r | r | r/w | r/w | r/w | r/w | r/w | r/w | r/w | r/w |
| Function | Exponent | Mantissa | ||||||||||||||
| Default Value | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |