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Diffstat (limited to 'Projects/XPLAINBridge/Lib/SoftUART.c')
| -rw-r--r-- | Projects/XPLAINBridge/Lib/SoftUART.c | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/Projects/XPLAINBridge/Lib/SoftUART.c b/Projects/XPLAINBridge/Lib/SoftUART.c deleted file mode 100644 index 5c0e3c8cd9..0000000000 --- a/Projects/XPLAINBridge/Lib/SoftUART.c +++ /dev/null @@ -1,156 +0,0 @@ -/* - LUFA Library - Copyright (C) Dean Camera, 2017. - - dean [at] fourwalledcubicle [dot] com - www.lufa-lib.org -*/ - -/* - Copyright 2010 David Prentice (david.prentice [at] farming [dot] uk) - Copyright 2010 Peter Danneger - Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com) - - Permission to use, copy, modify, distribute, and sell this - software and its documentation for any purpose is hereby granted - without fee, provided that the above copyright notice appear in - all copies and that both that the copyright notice and this - permission notice and warranty disclaimer appear in supporting - documentation, and that the name of the author not be used in - advertising or publicity pertaining to distribution of the - software without specific, written prior permission. - - The author disclaims all warranties with regard to this - software, including all implied warranties of merchantability - and fitness. In no event shall the author be liable for any - special, indirect or consequential damages or any damages - whatsoever resulting from loss of use, data or profits, whether - in an action of contract, negligence or other tortious action, - arising out of or in connection with the use or performance of - this software. -*/ - -/** \file - * - * Software UART for both data transmission and reception. This - * code continuously monitors the ring buffers set up by the main - * project source file and reads/writes data as it becomes available. - */ - -#include "SoftUART.h" - -/** Total number of bits remaining to be sent in the current frame */ -static uint8_t TX_BitsRemaining; - -/** Temporary data variable to hold the byte being transmitted as it is shifted out */ -static uint8_t TX_Data; - -/** Total number of bits remaining to be received in the current frame */ -static uint8_t RX_BitsRemaining; - -/** Temporary data variable to hold the byte being received as it is shifted in */ -static uint8_t RX_Data; - - -/** Initializes the software UART, ready for data transmission and reception into the global ring buffers. */ -void SoftUART_Init(void) -{ - /* Set TX pin to output high, enable RX pull-up */ - STXPORT |= (1 << STX); - STXDDR |= (1 << STX); - SRXPORT |= (1 << SRX); - - /* Enable INT0 for the detection of incoming start bits that signal the start of a byte */ - EICRA = (1 << ISC01); - EIMSK = (1 << INT0); - - /* Set the transmission and reception timer compare values for the default baud rate */ - SoftUART_SetBaud(9600); - - /* Setup reception timer compare ISR */ - TIMSK1 = (1 << OCIE1A); - - /* Setup transmission timer compare ISR and start the timer */ - TIMSK3 = (1 << OCIE3A); - TCCR3B = ((1 << CS30) | (1 << WGM32)); -} - -/** ISR to detect the start of a bit being sent to the software UART. */ -ISR(INT0_vect, ISR_BLOCK) -{ - /* Reset the number of reception bits remaining counter */ - RX_BitsRemaining = 8; - - /* Reset the bit reception timer to -(1/2) of the total bit time, so that the first data bit is - * sampled mid way through the total bit time, making reception more robust. - */ - TCNT1 = -(OCR1A >> 1); - - /* Check to see that the pin is still low (prevents glitches from starting a frame reception) */ - if (!(SRXPIN & (1 << SRX))) - { - /* Disable start bit detection ISR while the next byte is received */ - EIMSK = 0; - - /* Start the reception timer */ - TCCR1B = ((1 << CS10) | (1 << WGM12)); - } -} - -/** ISR to manage the reception of bits to the software UART. */ -ISR(TIMER1_COMPA_vect, ISR_BLOCK) -{ - /* Cache the current RX pin value for later checking */ - uint8_t SRX_Cached = (SRXPIN & (1 << SRX)); - - /* Check if reception has finished */ - if (RX_BitsRemaining) - { - /* Shift the current received bit mask to the next bit position */ - RX_Data >>= 1; - RX_BitsRemaining--; - - /* Store next bit into the received data variable */ - if (SRX_Cached) - RX_Data |= (1 << 7); - } - else - { - /* Disable the reception timer as all data has now been received, re-enable start bit detection ISR */ - TCCR1B = 0; - EIFR = (1 << INTF0); - EIMSK = (1 << INT0); - - /* Reception complete, store the received byte if stop bit valid */ - if (SRX_Cached) - RingBuffer_Insert(&UARTtoUSB_Buffer, RX_Data); - } -} - -/** ISR to manage the transmission of bits via the software UART. */ -ISR(TIMER3_COMPA_vect, ISR_BLOCK) -{ - /* Check if transmission has finished */ - if (TX_BitsRemaining) - { - /* Set the TX line to the value of the next bit in the byte to send */ - if (TX_Data & (1 << 0)) - STXPORT &= ~(1 << STX); - else - STXPORT |= (1 << STX); - - /* Shift the transmission byte to move the next bit into position and decrement the bits remaining counter */ - TX_Data >>= 1; - TX_BitsRemaining--; - } - else if (!(RX_BitsRemaining) && !(RingBuffer_IsEmpty(&USBtoUART_Buffer))) - { - /* Start bit - TX line low */ - STXPORT &= ~(1 << STX); - - /* Transmission complete, get the next byte to send (if available) */ - TX_Data = ~RingBuffer_Remove(&USBtoUART_Buffer); - TX_BitsRemaining = 9; - } -} - |