// ################################################################################################# // # << NEORV32 - SPI Bus Explorer Demo Program >> # // # ********************************************************************************************* # // # BSD 3-Clause License # // # # // # Copyright (c) 2024, 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. # // # # // # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS # // # 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, # // # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE # // # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED # // # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING # // # 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/main.c * @author Stephan Nolting * @brief SPI bus explorer (execute SPI transactions by hand). **************************************************************************/ #include #include /**********************************************************************//** * @name User configuration **************************************************************************/ /**@{*/ /** UART BAUD rate */ #define BAUD_RATE 19200 /**@}*/ // Global variables uint32_t spi_configured; // Prototypes void spi_cs(uint32_t type); void spi_trans(void); void spi_setup(void); uint32_t hexstr_to_uint(char *buffer, uint8_t length); void aux_print_hex_byte(uint8_t byte); /**********************************************************************//** * This program provides an interactive console to communicate with SPI devices. * * @note This program requires the UART and the SPI to be synthesized. * * @return Irrelevant. **************************************************************************/ int main() { char buffer[8]; int length = 0; // 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<<< SPI Bus Explorer >>>\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; } // info neorv32_uart0_printf("This program allows to create SPI transfers by hand.\n" "Type 'help' to see the help menu.\n\n"); // disable and reset SPI module neorv32_spi_disable(); spi_configured = 0; // SPI not configured yet // Main menu for (;;) { neorv32_uart0_printf("SPI_EXPLORER:> "); length = neorv32_uart0_scan(buffer, 15, 1); neorv32_uart0_printf("\n"); if (!length) // nothing to be done continue; // decode input and execute command if (!strcmp(buffer, "help")) { neorv32_uart0_printf("Available commands:\n" " help - show this text\n" " setup - configure SPI module\n" " en - enable single chip-select line (set low)\n" " dis - disable all chip-select lines (set high)\n" " trans - SPI data transmission (write & read to/from SPI)\n" "\n" "Configure the SPI module using 'setup'. Enable a certain module using 'cs-en',\n" "then transfer data using 'trans' and disable the module again using 'cs-dis'.\n" "\n"); } else if (!strcmp(buffer, "setup")) { spi_setup(); } else if (!strcmp(buffer, "en")) { spi_cs(1); } else if (!strcmp(buffer, "dis")) { spi_cs(0); } else if (!strcmp(buffer, "trans")) { spi_trans(); } else { neorv32_uart0_printf("Invalid command. Type 'help' to see all commands.\n"); } } return 0; } /**********************************************************************//** * Enable or disable chip-select line * * @param[in] type 0=disable, 1=enable **************************************************************************/ void spi_cs(uint32_t type) { char terminal_buffer[2]; uint8_t channel; if (spi_configured == 0) { neorv32_uart0_printf("SPI module not configured yet! Use 'setup' to configure SPI module.\n"); return; } if (type) { neorv32_uart0_printf("Chip-select line to ENABLE (set low) [0..7]: "); while (1) { neorv32_uart0_scan(terminal_buffer, 2, 1); // 1 hex char plus '\0' channel = (uint8_t)hexstr_to_uint(terminal_buffer, strlen(terminal_buffer)); if (channel > 7) { neorv32_uart0_printf("\nInvalid channel selection!\n"); return; } else { neorv32_uart0_printf("\n"); break; } } neorv32_spi_cs_en(channel); } else { neorv32_uart0_printf("Disabling chip select lines.\n"); neorv32_spi_cs_dis(); } } /**********************************************************************//** * SPI data transfer **************************************************************************/ void spi_trans(void) { char terminal_buffer[4]; if (spi_configured == 0) { neorv32_uart0_printf("SPI module not configured yet! Use 'setup' to configure SPI module.\n"); return; } neorv32_uart0_printf("Enter TX data (2 hex chars): 0x"); neorv32_uart0_scan(terminal_buffer, 2+1, 1); uint32_t tx_data = (uint32_t)hexstr_to_uint(terminal_buffer, strlen(terminal_buffer)); uint32_t rx_data = neorv32_spi_trans(tx_data); neorv32_uart0_printf("\nTX data: 0x"); aux_print_hex_byte(tx_data); neorv32_uart0_printf("\nRX data: 0x"); aux_print_hex_byte(rx_data); neorv32_uart0_printf("\n"); } /**********************************************************************//** * Configure SPI module **************************************************************************/ void spi_setup(void) { const uint32_t PRSC_LUT[8] = {2, 4, 8, 64, 128, 1024, 2048, 4096}; char terminal_buffer[9]; uint8_t spi_prsc, clk_div, clk_phase, clk_pol; uint32_t tmp; // ---- SPI clock ---- while (1) { neorv32_uart0_printf("Select SPI clock prescaler (0..7): "); neorv32_uart0_scan(terminal_buffer, 2, 1); tmp = (uint32_t)hexstr_to_uint(terminal_buffer, strlen(terminal_buffer)); if (tmp > 8) { neorv32_uart0_printf("\nInvalid selection!\n"); } else { spi_prsc = (uint8_t)tmp; break; } } neorv32_uart0_printf("\nEnter clock divider (0..15, as one hex char): "); neorv32_uart0_scan(terminal_buffer, 2, 1); clk_div = (uint8_t)hexstr_to_uint(terminal_buffer, strlen(terminal_buffer)); uint32_t clock = NEORV32_SYSINFO->CLK / (2 * PRSC_LUT[spi_prsc] * (1 + clk_div)); neorv32_uart0_printf("\n+ New SPI clock speed = %u Hz\n", clock); // ---- SPI clock mode ---- while (1) { neorv32_uart0_printf("Select SPI clock mode (0..3): "); neorv32_uart0_scan(terminal_buffer, 2, 1); tmp = (uint32_t)hexstr_to_uint(terminal_buffer, strlen(terminal_buffer)); if (tmp > 4) { neorv32_uart0_printf("\nInvalid selection!\n"); } else { clk_pol = (uint8_t)((tmp >> 1) & 1); clk_phase = (uint8_t)(tmp & 1); break; } } neorv32_uart0_printf("\n+ New SPI clock mode = %u\n\n", tmp); neorv32_spi_setup(spi_prsc, clk_div, clk_phase, clk_pol, 0); spi_configured = 1; // SPI is configured now } /**********************************************************************//** * Helper function to convert N hex chars string into uint32_T * * @param[in,out] buffer Pointer to array of chars to convert into number. * @param[in,out] length Length of the conversion string. * @return Converted number. **************************************************************************/ uint32_t hexstr_to_uint(char *buffer, uint8_t length) { uint32_t res = 0, d = 0; char c = 0; while (length--) { c = *buffer++; if ((c >= '0') && (c <= '9')) d = (uint32_t)(c - '0'); else if ((c >= 'a') && (c <= 'f')) d = (uint32_t)((c - 'a') + 10); else if ((c >= 'A') && (c <= 'F')) d = (uint32_t)((c - 'A') + 10); else d = 0; res = res + (d << (length*4)); } return res; } /**********************************************************************//** * Print HEX byte. * * @param[in] byte Byte to be printed as 2-cahr hex value. **************************************************************************/ void aux_print_hex_byte(uint8_t byte) { static const char symbols[] = "0123456789abcdef"; neorv32_uart0_putc(symbols[(byte >> 4) & 0x0f]); neorv32_uart0_putc(symbols[(byte >> 0) & 0x0f]); }