Overview
========
The i2c_dma_b2b_transfer_master example shows how to use i2c driver as master to do board to board transfer 
with DMA:

In this example, one i2c instance as master and another i2c instance on the other board as slave. Master sends a 
piece of data to slave, and receive a piece of data from slave. This example checks if the data received from 
slave is correct.

Toolchain supported
===================
- IAR embedded Workbench  9.10.2
- Keil MDK  5.34
- GCC ARM Embedded  10.2.1
- MCUXpresso  11.5.0

Hardware requirements
=====================
- Micro USB cable
- Two LPCXpresso55S16 boards
- Personal Computer

Board settings
==============
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MASTER_BOARD        CONNECTS TO         SLAVE_BOARD
Pin Name   Board Location     Pin Name   Board Location
I2C_SCL    J9-2               I2C_SCL    J9-2
I2C_SDA    J9-4               I2C_SDA    J9-4
GND        J9-8               GND        J9-8    
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The jumper setting:
    Default jumpers configuration does not work,  you will need to add JP20 and JP21 (JP22 optional for ADC use)
    
Prepare the Demo
================
1. Connect a micro USB cable between the PC host and the LPC-Link USB port (J1) on the board.
2. Open a serial terminal on PC for JLink serial device with these settings:
   - 115200 baud rate
   - 8 data bits
   - No parity
   - One stop bit
   - No flow control
3. Download the program to the target board.
4. Either press the reset button on your board or launch the debugger in your IDE to begin running
   the demo.

Running the demo
================
The following message shows in the terminal if the example runs successfully.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I2C board2board DMA example -- Master transfer.
Master will send data :
0x 0  0x 1  0x 2  0x 3  0x 4  0x 5  0x 6  0x 7  
0x 8  0x 9  0x a  0x b  0x c  0x d  0x e  0x f  
0x10  0x11  0x12  0x13  0x14  0x15  0x16  0x17  
0x18  0x19  0x1a  0x1b  0x1c  0x1d  0x1e  0x1f  

Receive sent data from slave :
0x 0  0x 1  0x 2  0x 3  0x 4  0x 5  0x 6  0x 7  
0x 8  0x 9  0x a  0x b  0x c  0x d  0x e  0x f  
0x10  0x11  0x12  0x13  0x14  0x15  0x16  0x17  
0x18  0x19  0x1a  0x1b  0x1c  0x1d  0x1e  0x1f  


End of I2C example .
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
