neorv32/sw/example/demo_spi_irq/main.c

138 lines
6.3 KiB
C

// #################################################################################################
// # << NEORV32 - IRQ driven SPI transfer application example >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2023, Stephan Nolting. All rights reserved. #
// # #
// # Redistribution and use in source and binary forms, with or without modification, are #
// # permitted provided that the following conditions are met: #
// # #
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
// # conditions and the following disclaimer. #
// # #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
// # conditions and the following disclaimer in the documentation and/or other materials #
// # provided with the distribution. #
// # #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
// # endorse or promote products derived from this software without specific prior written #
// # permission. #
// # #
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// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
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// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
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// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file demo_spi_irq/main.c
* @author Andreas Kaeberlein
* @brief Example of an ISR driven SPI transfer
**************************************************************************/
#include <neorv32.h>
#include <string.h>
#include "neorv32_spi_irq.h"
/**********************************************************************//**
* @name User configuration
**************************************************************************/
/**@{*/
/** UART BAUD rate */
#define BAUD_RATE 19200
/**@}*/
// Global variables
t_neorv32_spi g_neorv32_spi;
/**********************************************************************//**
* SPI Interrupt Handler
*
* @note Captures/Transmits the data to the SPI core
*
* @return void.
**************************************************************************/
void spi_irq_handler(void)
{
neorv32_spi_isr(&g_neorv32_spi);
}
/**********************************************************************//**
* This program demonstrates the usage of an ISR driven SPI transfer
*
* @note This program requires the UART and the SPI to be synthesized.
*
* @return Irrelevant.
**************************************************************************/
int main()
{
// SPI Transceiver buffer
uint8_t uint8MemBuf[10];
// capture all exceptions and give debug info via UART
// this is not required, but keeps us safe
neorv32_rte_setup();
// setup UART at default baud rate, no interrupts
neorv32_uart0_setup(BAUD_RATE, 0);
// check if UART0 unit is implemented at all
if (neorv32_uart0_available() == 0) {
return 1;
}
// intro
neorv32_uart0_printf("\n<<< IRQ driven SPI transfer >>>\n\n");
// check if SPI unit is implemented at all
if (neorv32_spi_available() == 0) {
neorv32_uart0_printf("ERROR! No SPI unit implemented.");
return 1;
}
// enable IRQ system
neorv32_rte_handler_install(SPI_RTE_ID, spi_irq_handler); // SPI to RTE
neorv32_cpu_csr_set(CSR_MIE, 1 << SPI_FIRQ_ENABLE); // enable SPI FIRQ
neorv32_cpu_csr_set(CSR_MSTATUS, 1 << CSR_MSTATUS_MIE); // enable machine-mode interrupts
// SPI
// SPI Control
neorv32_spi_init(&g_neorv32_spi);
// Configure
neorv32_spi_disable();
// neorv32_spi_setup(int prsc, int cdiv, int clk_phase, int clk_polarity, uint32_t irq_mask)
neorv32_spi_setup(0, 0, 0, 0, 1<<SPI_CTRL_IRQ_TX_EMPTY); // spi mode 0, IRQ: 0-: PHY going idle, 10: TX fifo less than half full, 11: TX fifo empty
neorv32_spi_enable();
// IRQ based data transfer
memset(uint8MemBuf, 0, sizeof(uint8MemBuf)); // fill with 0's
uint8MemBuf[0] = 0x3;
uint8MemBuf[1] = 0x0;
uint8MemBuf[2] = 0x0;
uint8MemBuf[3] = 0x0;
// int neorv32_spi_rw(t_neorv32_spi *self, uint8_t csn, void *spi, uint32_t len)
neorv32_spi_rw(&g_neorv32_spi, 0, uint8MemBuf, sizeof(uint8MemBuf)); // send/receive data
// Wait for complete, free for other jobs
while ( neorv32_spi_rw_busy(&g_neorv32_spi) ) {
__asm("nop");
}
// stop program counter
while ( 1 ) { }
return 0;
}