82 lines
2.9 KiB
C
82 lines
2.9 KiB
C
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// FIFO.c
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// Runs on any Microcontroller
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// Provide functions that initialize a FIFO, put data in, get data out,
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// and return the current size. The file includes a transmit FIFO
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// using index implementation and a receive FIFO using pointer
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// implementation. Other index or pointer implementation FIFOs can be
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// created using the macros supplied at the end of the file.
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// Daniel Valvano
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// November 18, 2022
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/* This example accompanies the book
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"Embedded Systems: Real Time Interfacing to the Arm Cortex M3",
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ISBN: 978-1463590154, Jonathan Valvano, copyright (c) 2011
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Programs 3.7, 3.8., 3.9 and 3.10 in Section 3.7
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Copyright 2022 by Jonathan W. Valvano, valvano@mail.utexas.edu
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You may use, edit, run or distribute this file
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as long as the above copyright notice remains
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THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
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OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
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VALVANO SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL,
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OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
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For more information about my classes, my research, and my books, see
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http://users.ece.utexas.edu/~valvano/
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*/
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#include <ti/devices/msp/msp.h>
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#include "../inc/FIFO.h"
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// Two-index implementation of the transmit FIFO
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// can hold 0 to TXFIFOSIZE-1 elements
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uint32_t volatile TxPutI; // where to put next
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uint32_t volatile TxGetI; // where to get next
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char static TxFifo[TXFIFOSIZE];
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void TxFifo_Init(void){
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TxPutI = TxGetI = 0; // empty
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}
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int TxFifo_Put(char data){
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uint32_t newPutI = (TxPutI+1)&(TXFIFOSIZE-1);
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if(newPutI == TxGetI) return 0; // fail if full
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TxFifo[TxPutI] = data; // save in Fifo
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TxPutI = newPutI; // next place to put
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return 1;
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}
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char TxFifo_Get(void){char data;
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if(TxGetI == TxPutI) return 0; // fail if empty
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data = TxFifo[TxGetI]; // retrieve data
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TxGetI = (TxGetI+1)&(TXFIFOSIZE-1); // next place to get
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return data;
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}
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uint32_t TxFifo_Size(void){
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return (TxPutI-TxGetI)&(TXFIFOSIZE-1);
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}
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// Two-index implementation of the receive FIFO
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// can hold 0 to RXFIFOSIZE-1 elements
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uint32_t volatile RxPutI; // where to put next
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uint32_t volatile RxGetI; // where to get next
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char static RxFifo[RXFIFOSIZE];
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void RxFifo_Init(void){
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RxPutI = RxGetI = 0; // empty
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}
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int RxFifo_Put(char data){
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uint32_t newPutI = (RxPutI+1)&(RXFIFOSIZE-1);
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if(newPutI == RxGetI) return 0; // fail if full
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RxFifo[RxPutI] = data; // save in Fifo
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RxPutI = newPutI; // next place to put
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return 1;
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}
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char RxFifo_Get(void){char data;
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if(RxGetI == RxPutI) return 0; // fail if empty
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data = RxFifo[RxGetI]; // retrieve data
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RxGetI = (RxGetI+1)&(RXFIFOSIZE-1); // next place to get
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return data;
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}
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uint32_t RxFifo_Size(void){
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return (RxPutI-RxGetI)&(RXFIFOSIZE-1);
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}
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