NXP Semiconductors QorIQ LX2160A - Temperature measurement

Table 19. GPIO mapping (continued)
LX2160A pin LX2160A GPIO function LX2160A primary function
EVT2_B GPIO3[14]
EVT3_B GPIO3[15]
EVT4_B GPIO3[16]
Because all IRQ signals have a pull-up, GPIO pins programmed to input mode default to “1”.
NOTE
2.16 Temperature measurement
The LX2160A processor has two thermal monitoring diodes, which can be measured on the LX2160ARDB by two thermal monitor
devices, SA56004ED and SA56004FD, from NXP. Software can perform direct die temperature readings with an accuracy of ±1
°C. See I2C interface for addressing information.
In addition to monitoring, the SA56004ED and SA56004FD devices can also trigger alarms upon detecting thermal problems. To
do this, the thermal warning and thermal alert signals from these devices are connected to the system controller (CPLD), as well
as to status LEDs. The CPLD uses these signals to power down the system, to protect the processor from over-temperature
damage.
The LX2160ARDB thermal management scheme is shown in the figure below.

 



THERM_WRN_B
DUT
I2C bus
THERM_FLT_B
VDD
SD_SVDD
SD_OVDD
GVDD
.....
CPLD
Device power
Indicator
1U
PSU
Shut down
.....
Thermal sensor 1
(SA56004ED)
TEMP_DIODE1_P
TEMP_DIODE1_N
TD1_ANODE
TD1_CATHODE
TD2_ANODE
TD2_CATHODE
Thermal sensor 2
(SA56004FD)
TEMP_DIODE2_P
TEMP_DIODE2_N
Figure 28. Thermal management scheme
Thermal monitoring happens with no programming involved. However, if the thermal limit, by default set as 85 °C, is higher than
desired, it will need to be re-programmed. To change the thermal trip point, issue the I2C writes listed in the table below.
NXP Semiconductors
LX2160ARDB Functional Description
QorIQ LX2160A Reference Design Board Reference Manual, Rev. 4, 07/2020
Reference Manual 41 / 116