Preliminary User's Manual l TQMa8Xx UM 0002 l © 2018, TQ-Systems GmbH
Page 13
3.2.2.5
EEPROM with temperature sensor
A serial EEPROM including temperature sensor, controlled by the I2C1 bus, is assembled.
The lower 128 bytes (addresses 00h to 7Fh) can be set to Permanent Write Protected (PWP) mode or Reversible Write Protected
(RWP) mode by software. The upper 128 bytes (addresses 80h to FFh) cannot be write-protected and can be used for general
data storage. The EEPROM also provides a temperature sensor to monitor the temperature of the TQMa8Xx.
The following table shows details of the Manufacturer EEPROM.
Table 8:
Manufacturer EEPROM
Manufacturer
Part number
Size
Temperature range
NXP
SE97BTP
2 × 128 bytes
–45 °C to +85 °C
The device has the following I
2
C addresses:
o
EEPROM (normal):
0x51 / 101 0001b
o
EEPROM (Protection mode):
0x31 / 011 0001b
o
Temperature sensor:
0x19 / 001 1001b
The following illustration shows the interface of the temperature sensor to the i.MX 8X.
Illustration 7:
Block diagram temperature sensor interface
The EEPROM with temperature sensor (D7) is assembled on the bottom side of the TQMa8Xx, see Illustration 15.
The overtemperature output of the sensor is connected as open drain to connector X1-4 (TEMP_EVENT#).
A pull-up to a maximum voltage of 3.6 V must be provided on the carrier board.
The following table shows details of the temperature sensor.
Table 9:
Temperature sensor SE97BTP
Manufacturer
Part number
Resolution
Accuracy
Temperature range
NXP
SE97BTP
11 bits
Max. ±3 °C
–40 °C to +125 °C
3.2.3
RTC
In addition to the i.MX 8X-internal RTC, the TQMa8Xx provides a discrete RTC DS1339U as assembly option.
The accuracy of the RTC is essentially determined by the characteristics of the quartz used.
The quartzes used on the TQMa8Xx have a standard frequency tolerance of ±20 ppm at +25 °C.
The RTC is connected to the I2C1 bus.
The RTC has I
2
C address
0x68 / 110 1000b
Note: Power supply for i.MX 8X-internal RTC
The i.MX 8X-internal RTC can always be used in ON mode, but resets itself when the module supply
is switched off, since the SNVS domain of the i.MX 8X is then no longer supplied.
