#include "driverlib.h"

Macros
#define	SPICLK 500000

Functions
void	main (void)

void	USCI_A0_ISR (void)

Variables
uint8_t	transmitData = 0x00

uint8_t	receiveData = 0x00

uint8_t	returnValue = 0x00

Macro Definition Documentation

◆ SPICLK

#define SPICLK 500000

This example shows how SPI master talks to SPI slave using 3-wire mode. Incrementing data is sent by the master starting at 0x01. Received data is expected to be same as the previous transmission. USCI RX ISR is used to handle communication with the CPU, normally in LPM0. If high, P1.0 indicates valid data reception. Because all execution after LPM0 is in ISRs, initialization waits for DCO to stabilize against ACLK. ACLK = ~32.768kHz, MCLK = SMCLK = DCO ~ 1048kHz. BRCLK = SMCLK/2

Use with SPI Slave Data Echo code example. If slave is in debug mode, P1.1 slave reset signal conflicts with slave's JTAG; to work around, use IAR's "Release JTAG on Go" on slave device. If breakpoints are set in slave RX ISR, master must stopped also to avoid overrunning slave RXBUF.

             MSP430F5438A
            -----------------
       /|\ |                 |
        |  |                 |

Master—+->|RST | | | | P3.4|-> Data Out (UCA0SIMO) | | | P3.5|<- Data In (UCA0SOMI) | | | P3.0|-> Serial Clock Out (UCA0CLK)

This example uses the following peripherals and I/O signals. You must review these and change as needed for your own board:

SPI peripheral
GPIO Port peripheral (for SPI pins)
UCA0SIMO
UCA0SOMI
UCA0CLK

This example uses the following interrupt handlers. To use this example in your own application you must add these interrupt handlers to your vector table.

USCI_A0_VECTOR

Definition at line 82 of file usci_a_spi_ex1_master.c.

Function Documentation

◆ main()

void main ( void )

Definition at line 87 of file usci_a_spi_ex1_master.c.

References __delay_cycles(), GPIO_setOutputHighOnPin(), GPIO_setOutputLowOnPin(), param, returnValue, SPICLK, STATUS_FAIL, and transmitData.

◆ USCI_A0_ISR()

void USCI_A0_ISR ( void )

Definition at line 175 of file usci_a_spi_ex1_master.c.

References __delay_cycles(), receiveData, and transmitData.

Variable Documentation

◆ receiveData

uint8_t receiveData = 0x00

Definition at line 84 of file usci_a_spi_ex1_master.c.

Referenced by USCI_A0_ISR().

◆ returnValue

uint8_t returnValue = 0x00

Definition at line 85 of file usci_a_spi_ex1_master.c.

Referenced by main().

◆ transmitData

uint8_t transmitData = 0x00