Preston Ernst
-data logging revision
Diff: sw_fifo.cpp
- Revision:
- 2:92c25cb669f4
- Parent:
- 1:25a2b47ca291
--- a/sw_fifo.cpp Thu Aug 05 08:27:51 2021 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,285 +0,0 @@
-////////////////////////////////////////////////////////////////////////////////////////
-/* enter necessary header files for proper interrupt vector and UART/USART visibility */
-////////////////////////////////////////////////////////////////////////////////////////
-
-#include <sw_fifo.h>
-#include "uart_comm_thread.h"
-
-typedef struct {
- uint8_t data_buf[FIFO_BUFFER_SIZE]; // FIFO buffer
- uint16_t i_first; // index of oldest data byte in buffer
- uint16_t i_last; // index of newest data byte in buffer
- uint16_t num_bytes; // number of bytes currently in buffer
-}sw_fifo_typedef;
-
-sw_fifo_typedef rx_fifo = { {0}, 0, 0, 0 }; // declare a receive software buffer
-sw_fifo_typedef tx_fifo = { {0}, 0, 0, 0 }; // declare a transmit software buffer
-
-
-/***************************************************************************************************************/
-// UART receive interrupt sub-routine
-// - interrupts when valid data exists in rx hardware buffer
-// - checks if there's room in the rx software buffer
-// - if there's room, it transfers the received data into the sw buffer
-// - automatically handles "uart_rx_buffer_full_flag"
-// - sets overflow flag upon software buffer overflow (doesn't overwrite existing data)
-//////////////////////////////////////////////
-/* enter name of UART RX IRQ Handler here */ {
-//////////////////////////////////////////////
-
- /* Explicitly clear the source of interrupt if necessary */
-
- if(rx_fifo.num_bytes == FIFO_BUFFER_SIZE) { // if the sw buffer is full
- uart_rx_fifo_ovf_flag = 1; // set the overflow flag
- }else if(rx_fifo.num_bytes < FIFO_BUFFER_SIZE) { // if there's room in the sw buffer
-
- ///////////////////////////////////////////////////
- /* read error/status reg here if desired */
- /* handle any hardware RX errors here if desired */
- ///////////////////////////////////////////////////
-
- /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- rx_fifo.data_buf[rx_fifo.i_last] = /* enter pointer to UART rx hardware buffer here */ // store the received data as the newest data element in the sw buffer
- /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-
- rx_fifo.i_last++; // increment the index of the most recently added element
- rx_fifo.num_bytes++; // increment the bytes counter
- }
- if(rx_fifo.num_bytes == FIFO_BUFFER_SIZE) { // if sw buffer just filled up
- uart_rx_fifo_full_flag = 1; // set the RX FIFO full flag
- }
- if(rx_fifo.i_last == FIFO_BUFFER_SIZE) { // if the index has reached the end of the buffer,
- rx_fifo.i_last = 0; // roll over the index counter
- }
- uart_rx_fifo_not_empty_flag = 1; // set received-data flag
-} // end UART RX IRQ handler
-/***************************************************************************************************************/
-
-
-/***************************************************************************************************************/
-// UART transmit interrupt sub-routine
-// - interrupts when the tx hardware buffer is empty
-// - checks if data exists in the tx software buffer
-// - if data exists, it places the oldest element of the sw buffer into the tx hardware buffer
-// - if the sw buffer is emptied, it disables the "hw buffer empty" interrupt
-// - automatically handles "uart_tx_buffer_full_flag"
-//////////////////////////////////////////////
-/* enter name of UART TX IRQ Handler here */ {
-//////////////////////////////////////////////
-
- /* Explicitly clear the source of interrupt if necessary */
-
- if(tx_fifo.num_bytes == FIFO_BUFFER_SIZE) { // if the sw buffer is full
- uart_tx_fifo_full_flag = 0; // clear the buffer full flag because we are about to make room
- }
- if(tx_fifo.num_bytes > 0) { // if data exists in the sw buffer
-
- ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- /* enter pointer to UART tx hardware buffer here */ = tx_fifo.data_buf[tx_fifo.i_first]; // place oldest data element in the TX hardware buffer
- ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-
- tx_fifo.i_first++; // increment the index of the oldest element
- tx_fifo.num_bytes--; // decrement the bytes counter
- }
- if(tx_fifo.i_first == FIFO_BUFFER_SIZE) { // if the index has reached the end of the buffer,
- tx_fifo.i_first = 0; // roll over the index counter
- }
- if(tx_fifo.num_bytes == 0) { // if no more data exists
-
- uart_tx_fifo_not_empty_flag = 0; // clear flag
-
- //////////////////////////////////////////////////////////////////////////
- /* disable UART "TX hw buffer empty" interrupt here */
- /* if using shared RX/TX hardware buffer, enable RX data interrupt here */
- //////////////////////////////////////////////////////////////////////////
-
- }
-}// end UART TX IRQ handler
-/***************************************************************************************************************/
-
-
-/***************************************************************************************************************/
-// UART data transmit function
-// - checks if there's room in the transmit sw buffer
-// - if there's room, it transfers data byte to sw buffer
-// - automatically handles "uart_tx_buffer_full_flag"
-// - sets the overflow flag upon software buffer overflow (doesn't overwrite existing data)
-// - if this is the first data byte in the buffer, it enables the "hw buffer empty" interrupt
-void uart_send_byte(uint8_t byte) {
-
- ///////////////////////////////////////////////////////////
- /* disable interrupts while manipulating buffer pointers */
- ///////////////////////////////////////////////////////////
-
- if(tx_fifo.num_bytes == FIFO_BUFFER_SIZE) { // no room in the sw buffer
- uart_tx_fifo_ovf_flag = 1; // set the overflow flag
- }else if(tx_fifo.num_bytes < FIFO_BUFFER_SIZE) { // if there's room in the sw buffer
- tx_fifo.data_buf[tx_fifo.i_last] = byte; // transfer data byte to sw buffer
- tx_fifo.i_last++; // increment the index of the most recently added element
- tx_fifo.num_bytes++; // increment the bytes counter
- }
- if(tx_fifo.num_bytes == FIFO_BUFFER_SIZE) { // if sw buffer is full
- uart_tx_fifo_full_flag = 1; // set the TX FIFO full flag
- }
- if(tx_fifo.i_last == FIFO_BUFFER_SIZE) { // if the "new data" index has reached the end of the buffer,
- tx_fifo.i_last = 0; // roll over the index counter
- }
-
- ///////////////////////
- /* enable interrupts */
- ///////////////////////
-
- if(tx_fifo.num_bytes > 0) { // if there is data in the buffer
-
- uart_tx_fifo_not_empty_flag = 1; // set flag
-
- ///////////////////////////////////////////////////////////////////////////
- /* if using shared RX/TX hardware buffer, disable RX data interrupt here */
- /* enable UART "TX hw buffer empty" interrupt here */
- ///////////////////////////////////////////////////////////////////////////
-
- }
-}
-/***************************************************************************************************************/
-
-
-/***************************************************************************************************************/
-// UART data receive function
-// - checks if data exists in the receive sw buffer
-// - if data exists, it returns the oldest element contained in the buffer
-// - automatically handles "uart_rx_buffer_full_flag"
-// - if no data exists, it clears the uart_rx_flag
-uint8_t uart_get_byte(void) {
-
- ///////////////////////////////////////////////////////////
- /* disable interrupts while manipulating buffer pointers */
- ///////////////////////////////////////////////////////////
-
- uint8_t byte = 0;
- if(rx_fifo.num_bytes == FIFO_BUFFER_SIZE) { // if the sw buffer is full
- uart_rx_fifo_full_flag = 0; // clear the buffer full flag because we are about to make room
- }
- if(rx_fifo.num_bytes > 0) { // if data exists in the sw buffer
- byte = rx_fifo.data_buf[rx_fifo.i_first]; // grab the oldest element in the buffer
- rx_fifo.i_first++; // increment the index of the oldest element
- rx_fifo.num_bytes--; // decrement the bytes counter
- }else{ // RX sw buffer is empty
- uart_rx_fifo_not_empty_flag = 0; // clear the rx flag
- }
- if(rx_fifo.i_first == FIFO_BUFFER_SIZE) { // if the index has reached the end of the buffer,
- rx_fifo.i_first = 0; // roll over the index counter
- }
-
- ///////////////////////
- /* enable interrupts */
- ///////////////////////
-
- return byte; // return the data byte
-}
-/***************************************************************************************************************/
-sw_fifo.h
-sw_fifo.h (1.5 KB)
-#define FIFO_BUFFER_SIZE 128 // software buffer size (in bytes)
-
-// UART data transmit function
-// - checks if there's room in the transmit sw buffer
-// - if there's room, it transfers data byte to sw buffer
-// - automatically handles "uart_tx_buffer_full_flag"
-// - sets the overflow flag upon software buffer overflow (doesn't overwrite existing data)
-// - if this is the first data byte in the buffer, it enables the "hw buffer empty" interrupt
-void uart_send_byte(uint8_t byte);
-
-
-// UART data receive function
-// - checks if data exists in the receive sw buffer
-// - if data exists, it returns the oldest element contained in the buffer
-// - automatically handles "uart_rx_buffer_full_flag"
-// - if no data exists, it clears the uart_rx_flag
-uint8_t uart_get_byte(void);
-
-volatile extern uint8_t uart_rx_fifo_not_empty_flag; // this flag is automatically set and cleared by the software buffer
-volatile extern uint8_t uart_rx_fifo_full_flag; // this flag is automatically set and cleared by the software buffer
-volatile extern uint8_t uart_rx_fifo_ovf_flag; // this flag is not automatically cleared by the software buffer
-volatile extern uint8_t uart_tx_fifo_full_flag; // this flag is automatically set and cleared by the software buffer
-volatile extern uint8_t uart_tx_fifo_ovf_flag; // this flag is not automatically cleared by the software buffer
-volatile extern uint8_t uart_tx_fifo_not_empty_flag; // this flag is automatically set and cleared by the software buffer
-
-// What I should post into the main:
-/////////////////////////////////////////////////////////////////////////
-/////////////////////////////////////////////////////////////////////////
-
-/*
-#include <sw_fifo.h> // make software buffer visible to this file
-
-volatile uint8_t uart_rx_fifo_not_empty_flag = 0;
-volatile uint8_t uart_rx_fifo_full_flag = 0;
-volatile uint8_t uart_rx_fifo_ovf_flag = 0;
-volatile uint8_t uart_tx_fifo_full_flag = 0;
-volatile uint8_t uart_tx_fifo_ovf_flag = 0;
-volatile uint8_t uart_tx_fifo_not_empty_flag = 0;
-
-int main (void) {
- uint8_t i = 0;
- uint8_t rx_data = 0;
-
- // initialize clocks
- // disable global interrupts
- // initialize gpio
- // initialize uart/usart
-
- // enable "UART RX" interrupt and "TX hardware buffer empty" interrupt
- // enable global interrupts
-
- while(uart_tx_fifo_full_flag); // wait for room to open up in the software buffer
- uart_send_byte('A'); // transmit ASCII character 'A'
- while(uart_tx_fifo_full_flag);
- uart_send_byte(0x41); // transmit ASCII character 'A'
-
- // transmit ASCII characters 1-5
- for(i=0; i<5; i++) {
- while(uart_tx_fifo_full_flag);
- uart_send_byte(i+48);
- }
-
- while(1) {
- // enter sleep mode if supported (wake from UART Rx)
-
- while(uart_rx_fifo_not_empty_flag) { // if data exists in software buffer
- rx_data = uart_get_byte(); // grab first data byte from software buffer
-
- /* handle received byte as desired */
-
-
- uart_send_byte(rx_data); // example of how to echo received ASCII characters
- }
-
- // check for rx overflow condition
- if(uart_rx_fifo_ovf_flag) {
-
- /* handle rx overflow condition as desired */
-
- uart_rx_fifo_ovf_flag = 0; // clear the rx overflow flag
- }
-
- // check for tx overflow condition
- if(uart_tx_fifo_ovf_flag) {
-
- /* handle tx overflow condition as desired */
-
- uart_tx_fifo_ovf_flag = 0; // clear the tx overflow flag
- }
-
- // if you need to disable global interrupts, you should wait until the tx fifo is empty
- while(uart_tx_fifo_not_empty_flag);
- /* Disable global interrupts */
-
- /* Do something */
-
- /* Re-enable global interrupts */
- } // end while
-} // end main
-*/
-
-
-
-