NXP Semiconductors
UMxxxxx
Install Guide
All information provided in this document is subject to legal disclaimers.
Preliminary 1
— September 6, 2013
© NXP B.V. 2013. All rights reserved.
24 of 70
5.3
Bus One (Bus1)
There are two almost identical I2C Buses on the Fm+ Development Board (OM13260), called Bus1 and
Bus2. These share a ground and power connection but may be operated independently.
Note: The Bus Voltage for each I2C maybe different (for example 3.3V for one I2C bus, 5V for the
other I2C bus).
5.3.1
Bus 1 Master (MCU LPC1343)
Microcontroller (MCU) (LPC1343, IC5) serves as the Bus 1 Master and the USB Bridge. Firmware
installed on the Fm+ Development Board (OM13260) is stored in non-volatile memory, which has a
limit of 32kb. The MCU may be programmed through the USB port or the JTAG connector (CN 19),
using Single Wire Debug (SWD), see figure 5.5 and figure 5.6.
During programming or at other times it may be necessary to reset the MCU, by briefly shorting JP4,
see figure 5.6.
Note: An MCU Reset is not the same as an I2C Bus Reset. Resetting the MCU will not affect the I2C
Bus, unless the MCU firmware is designed to issue an I2C Bus Reset when it is reset.
Fig 5.5 MCU SWD Interface
Summary of Contents for OM13260
Page 71: ......