Contents
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 : used to configure SPI |
| SPSR | SPI status Register : |
| 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