Revision as of 19:07, 16 June 2015

Objective

LPC1768 SPI Block

The below block diagram shows the SPI input pins multiplexed with other GPIO pins.
The SPI pin can be enabled by configuring the corresponding PINSEL register to select SPI function.
When the SPI function is selected for that pin in the Pin Select register, other Digital signals are disconnected from the SPI input pins.

Port Pin	Pin Number	PINSEL_FUNC_0	PINSEL_FUNC_1	PINSEL_FUNC_2	PINSEL_FUNC_3
P0.15	47	GPIO	TXD1	SCK0	SCK
P0.16	48	GPIO	RXD1	SSEL0	SSEL
P0.17	46	GPIO	CTS1	MISO0	MISO
P0.18	45	GPIO	DCD1	MOSI0	MOSI

SPI Registers

Register	Description
SPCR	SPI Control Register
SPSR	Contains the data to be transmitted : used to configure SPI
SPDR	SPI Data Register : contains received data or data to be transmitted
SPCCR	SPI Clock Counter Register : used to control master SCK frequency

SPI Register Configuration

Steps for using SPI

Initialize SPI

Send Data

Receive Data

Code

Example 1

Using Explore Embedded Libraries

@@ Line 23: / Line 23: @@
 !Register || Description
 |-
-|SPCR|| Contains the recently received Data
+|SPCR|| SPI Control Register
 |-
-|SPSR|| Contains the data to be transmitted
+|SPSR|| Contains the data to be transmitted : used to configure SPI
 |-
-|SPDR|| FIFO Control Register
+|SPDR|| SPI Data Register : contains received data  or data to be transmitted
 |-
-|SPCCR|| Controls the UART frame formatting(Number of Data Bits, Stop bits)
+|SPCCR|| SPI Clock Counter Register : used to control master SCK frequency
-|-
-|DLL|| Least Significant Byte of the UART baud rate generator value.
-|-
-|DLM|| Most Significant Byte of the UART baud rate generator value.
 |}
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Difference between revisions of "LPC1768: SPI Programming"