SBOS441I September 2009 – October 2019 TMP431 , TMP432
PRODUCTION DATA.
TMP431 STATUS REGISTER (Read = 02h, Write = NA) | ||||||||
---|---|---|---|---|---|---|---|---|
BIT # | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
BIT NAME | BUSY | LHIGH | LLOW | RHIGH | RLOW | OPEN | RTHRM | LTHRM |
POR VALUE | 0(1) | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The TMP431 has a Status Register to report the state of the temperature comparators. Table 5 shows the Status Register bits. The Status Register is read-only and is read by reading from pointer address 02h.
The BUSY bit reads as 1 if the ADC is making a conversion. This bit reads as 0 if the ADC is not converting.
The OPEN bit reads as 1 if the remote transistor is detected as open from the last read of the Status Register. The OPEN status is only detected when the ADC is attempting to convert a remote temperature.
The RTHRM bit reads as 1 if the remote temperature exceeds the remote THERM limit and remains greater than the remote THERM limit less the value in the shared Hysteresis Register; see Figure 18.
The LTHRM bit reads as 1 if the local temperature exceeds the local THERM limit and remains greater than the local THERM limit less the value in the shared Hysteresis Register; see Figure 18.
The LHIGH and RHIGH bit values depend on the state of the AL/TH bit in the Configuration Register 1. If the AL/TH bit is ‘0’, the LHIGH bit reads as 1 if the local high limit was exceeded from the last clearing of the Status Register. The RHIGH bit reads as 1 if the remote high limit was exceeded from the last clearing of the Status Register. If the AL/TH bit is 1, the remote high limit and the local high limit are used to implement a THERM2 function. LHIGH reads as 1 if the local temperature exceeds the local high limit and remains greater than the local high limit less the value in the Hysteresis Register.
The RHIGH bit reads as 1 if the remote temperature has exceeded the remote high limit and remains greater than the remote high limit less the value in the Hysteresis Register.
The LLOW and RLOW bits are not affected by the AL/TH bit. The LLOW bit reads as 1 if the local low limit was exceeded from the last clearing of the Status Register. The RLOW bit reads as 1 if the remote low limit was exceeded from the last clearing of the Status Register.
The values of the LLOW, RLOW, and OPEN (as well as LHIGH and RHIGH when AL/TH is 0) are latched and read as 1 until the Status Register is read or a device reset occurs. These bits are cleared by reading the Status Register, provided that the condition causing the flag to be set no longer exists. The values of BUSY, LTHRM, and RTHRM (as well as LHIGH and RHIGH when ALERT/THERM2 is 1) are not latched and are not cleared by reading the Status Register. They always indicate the current state, and are updated appropriately at the end of the corresponding ADC conversion.
The TMP431 NORs LHIGH, LLOW, RHIGH, RLOW, and OPEN, so a status change for any of these flags from 0 to 1 automatically causes the ALERT pin to go low (only applies when the ALERT/THERM2 pin is configured for ALERT mode).