Overview
========
CMSIS-Driver defines generic peripheral driver interfaces for middleware making it reusable across a wide 
range of supported microcontroller devices. The API connects microcontroller peripherals with middleware 
that implements for example communication stacks, file systems, or graphic user interfaces. 
More information and usage method please refer to http://www.keil.com/pack/doc/cmsis/Driver/html/index.html.

The cmsis_spi_dma_b2b_transfer_slave example shows how to use spi driver as master to do board to board transfer 
with DMA:

In this example, one spi instance as master and another spi 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  9.40.1
- Keil MDK  5.38.1
- GCC ARM Embedded  12.2
- MCUXpresso  11.8.0

Hardware requirements
=====================
- Micro USB cable
- Two LPCXpresso55S36 boards
- Personal Computer

Board settings
==============
Short JP51 1-2, JP52 1-2.

Connect SPI master on board to SPI slave on other board
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Master_board(SPI2)           Slave_board(SPI2)                          
Pin Name   Board Location     Pin Name   Board Location                     
MISO       J122  pin 12       MISO       J122  pin 12 
MOSI       J8    pin 3        MOSI       J8    pin 3
SCK        J122  pin 8        SCK        J122  pin 8
SSEL0      J122  pin 6        SSEL0      J122  pin 6
GND        J92   pin 14       GND        J92   pin 14
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
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.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CMSIS SPI board2board DMA example -- Slave transfer.


 Slave example is running...


 Slave receive:
      0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
     10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
     20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
     30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
Succeed!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
