miriac SBC-S32V234 User Manual
V 1.0
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© MicroSys Electronics GmbH 2018
8
I²C Structure
The MPX-S32V234 operates three different I²C busses.
I²C Bus 0 and 1 are not used onboard the MPX-S32V234.
I²C Bus 2 controls all devices on the module.
8.1.1 Bus Map
I²C Bus 0:
Address
Reference
Device
Function
0x00-0x7F
---
---
External devices
Table 4 I²C0 bus map
I²C Bus 1:
Address
Reference
Device
Function
0x00-0x7F
---
---
External devices
Table 5 I²C1 bus map
I²C Bus 2:
Address
Reference
Device
Function
0x51
J25
PCF85263A
Real Time Clock
Table 6 I²C2 bus map
8.1.2 I²C Devices
8.1.2.1
RTC
The RTC PCF85263A provides year, month, day, weekday, hours, minutes,
seconds and 100th seconds. It can be protected against data loss by the backup
battery located on the CRX-S32V carrier.
It is accessible via I²C Bus 2 at the 7-bit address 0x51. It offers a time stamp input
and an interrupt output, which are both connected to the MCU.
8.1.2.2
RTC Backup Battery
The battery back can be accessed via the MXM connector on pin B133. It should
not exceed a maimum voltage of 3.3V. The battery type should have a nominal
voltage of 3.0V. The backup is necessary to keep time and date of the real-time
clock on the MPX-S32V234 module.
