Overview
========
The lpc_spi_half_duplex_int_transfer_slave example shows how to receive and transmit data to master board.

Notice: The SPI slave of this example uses interrupt mode. The data transfer size(not buffer size) is twice of
the master's transfer size. The first half of the transmission will receive data, and the second half will send
data back to master, so the address of the receive buffer is &rxDataPolling[64].

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

Toolchain supported
===================
- IAR embedded Workbench  8.32.3
- Keil MDK  5.27
- MCUXpresso  11.0.0
- GCC ARM Embedded  8.2.1

Hardware requirements
=====================
- Micro USB cable
- Two LPCXpresso54102 boards
- Personal Computer

Board settings
==============
Connect SPI master on board to SPI slave on other board
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Master - SPI0                  Slave - SPI0   
Pin Name   Board Location      Pin Name   Board Location            
MISO       J3 pin 3            MISO       J3 pin 3                     
MOSI       J3 pin 2            MOSI       J3 pin 2                
SCK        J3 pin 4            SCK        J3 pin 4                 
SSEL0      J3 pin 1            SSEL0      J3 pin 1
GND        J3 pin 5            GND        J3 pin 5
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Prepare the Demo
================
1.  Connect a micro USB cable between the PC host and the CMSIS DAP USB port (J6) on the board
2.  Open a serial terminal with the following settings (See Appendix A in Getting started guide for description how to determine serial port number):
    - 115200 baud rate
    - 8 data bits
    - No parity
    - One stop bit
    - No flow control
3.  Download the program to the target board.
4.  Reset the SoC and run the project.

Running the demo
================
When the demo runs successfully, the log would be seen on the CMSIS DAP terminal like:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is slave example for SPI half-duplex interrupt transfer.
Slave is working....

The received data are:
  0x00  0x01  0x02  0x03  0x04  0x05  0x06  0x07  0x08  0x09  0x0A  0x0B  0x0C  0x0D  0x0E  0x0F
  0x10  0x11  0x12  0x13  0x14  0x15  0x16  0x17  0x18  0x19  0x1A  0x1B  0x1C  0x1D  0x1E  0x1F
  0x20  0x21  0x22  0x23  0x24  0x25  0x26  0x27  0x28  0x29  0x2A  0x2B  0x2C  0x2D  0x2E  0x2F
  0x30  0x31  0x32  0x33  0x34  0x35  0x36  0x37  0x38  0x39  0x3A  0x3B  0x3C  0x3D  0x3E  0x3F

Slave transfer completed.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Customization options
=====================

