X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/7f9f97c792dee6875fbca9806422bdd7d6c5a657..f64e3db07ac167bf0b64bf429a53721f1848e91d:/Projects/XPLAINBridge/Lib/SoftUART.c?ds=inline diff --git a/Projects/XPLAINBridge/Lib/SoftUART.c b/Projects/XPLAINBridge/Lib/SoftUART.c index bc0265378..0591284e6 100644 --- a/Projects/XPLAINBridge/Lib/SoftUART.c +++ b/Projects/XPLAINBridge/Lib/SoftUART.c @@ -1,143 +1,124 @@ -/* - LUFA Library - Copyright (C) Dean Camera, 2010. - - dean [at] fourwalledcubicle [dot] com - www.fourwalledcubicle.com -*/ - -/* - Copyright 2010 David Prentice (david.prentice [at] farming [dot] uk) - Copyright 2010 Peter Danneger - Copyright 2010 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 disclaim 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. -*/ - -#include "SoftUART.h" - -volatile uint8_t srx_done, stx_count; -volatile uint8_t srx_data, srx_mask, srx_tmp, stx_data; - -unsigned char SoftUART_IsReady(void) -{ - return !(stx_count); -} - -unsigned char SoftUART_TxByte(unsigned char c) -{ - while (stx_count); - - stx_data = ~c; - stx_count = 10; - - return c; -} - -unsigned char SoftUART_IsReceived(void) -{ - return srx_done; -} - -unsigned char SoftUART_RxByte(void) -{ - while (!(srx_done)); - - srx_done = 0; - - return srx_data; -} - -void SoftUART_Init(void) -{ - OCR2B = TCNT2 + 1; // force first compare - TCCR2A = (1 << COM2B1) | (1 << COM2B0); // T1 mode 0 - TCCR2B = (1 << FOC2B) | (1 << CS21); // CLK/8, T1 mode 0 - TIMSK2 = (1 << OCIE2B); // enable tx and wait for start - EICRA = (1 << ISC01); // -ve edge - EIMSK = (1 << INT0); // enable INT0 interrupt - - stx_count = 0; // nothing to send - srx_done = 0; // nothing received - STXPORT |= 1 << STX; // TX output - STXDDR |= 1 << STX; // TX output - SRXPORT |= (1 << SRX); // pullup on INT0 -} - -/* ISR to detect the start of a bit being sent from the transmitter. */ -ISR(INT0_vect) -{ - OCR2A = TCNT2 + (BIT_TIME / 8 * 3 / 2); // scan 1.5 bits after start - - srx_tmp = 0; // clear bit storage - srx_mask = 1; // bit mask - - TIFR2 = (1 << OCF2A); // clear pending interrupt - - if (!(SRXPIN & (1 << SRX))) // still low - { - TIMSK2 = (1 << OCIE2A) | (1 << OCIE2B); // wait for first bit - EIMSK &= ~(1 << INT0); - } -} - -/* ISR to manage the reception of bits to the transmitter. */ -ISR(TIMER2_COMPA_vect) -{ - if (srx_mask) - { - if (SRXPIN & (1 << SRX)) - srx_tmp |= srx_mask; - - srx_mask <<= 1; - - OCR2A += BIT_TIME / 8; // next bit slice - } - else - { - srx_done = 1; // mark rx data valid - srx_data = srx_tmp; // store rx data - TIMSK2 = (1 << OCIE2B); // enable tx and wait for start - EIMSK |= (1 << INT0); // enable START irq - EIFR = (1 << INTF0); // clear any pending - } -} - -/* ISR to manage the transmission of bits to the receiver. */ -ISR(TIMER2_COMPB_vect) -{ - OCR2B += BIT_TIME / 8; // next bit slice - - if (stx_count) - { - if (--stx_count != 9) // no start bit - { - if (!(stx_data & 1)) // test inverted data - TCCR2A = (1 << COM2B1) | (1 << COM2B0); - else - TCCR2A = (1 << COM2B1); - - stx_data >>= 1; // shift zero in from left - } - else - { - TCCR2A = (1 << COM2B1); // START bit - } - } -} +/* + LUFA Library + Copyright (C) Dean Camera, 2010. + + dean [at] fourwalledcubicle [dot] com + www.fourwalledcubicle.com +*/ + +/* + Copyright 2010 David Prentice (david.prentice [at] farming [dot] uk) + Copyright 2010 Peter Danneger + Copyright 2010 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 disclaim 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" + +static uint8_t TX_BitsRemaining, TX_Data; +static uint8_t RX_BitMask, RX_Data; + +void SoftUART_Init(void) +{ + OCR2B = TCNT2 + 1; // force first compare + TCCR2A = (1 << COM2B1) | (1 << COM2B0); // T1 mode 0 + TCCR2B = (1 << FOC2B) | (1 << CS21); // CLK/8, T1 mode 0 + TIMSK2 = (1 << OCIE2B); // enable tx and wait for start + EICRA = (1 << ISC01); // -ve edge + EIMSK = (1 << INT0); // enable INT0 interrupt + + STXPORT |= (1 << STX); // TX output + STXDDR |= (1 << STX); // TX output + SRXPORT |= (1 << SRX); // pullup on INT0 +} + +/* ISR to detect the start of a bit being sent to the software UART. */ +ISR(INT0_vect) +{ + OCR2A = TCNT2 + (uint16_t)((BIT_TIME / 8.0f) * 1.5f); // scan 1.5 bits after start + + RX_Data = 0; // clear bit storage + RX_BitMask = (1 << 0); // bit mask + + TIFR2 = (1 << OCF2A); // clear pending interrupt + + if (!(SRXPIN & (1 << SRX))) // still low + { + TIMSK2 = (1 << OCIE2A) | (1 << OCIE2B); // wait for first bit + EIMSK &= ~(1 << INT0); + } +} + +/* ISR to manage the reception of bits to the software UART. */ +ISR(TIMER2_COMPA_vect) +{ + if (RX_BitMask) + { + if (SRXPIN & (1 << SRX)) + RX_Data |= RX_BitMask; + + RX_BitMask <<= 1; + + OCR2A += BIT_TIME / 8; // next bit slice + } + else + { + RingBuffer_Insert(&UARTtoUSB_Buffer, RX_Data); + + TIMSK2 = (1 << OCIE2B); // enable tx and wait for start + EIMSK |= (1 << INT0); // enable START irq + EIFR = (1 << INTF0); // clear any pending + } +} + +/* ISR to manage the transmission of bits via the software UART. */ +ISR(TIMER2_COMPB_vect) +{ + OCR2B += BIT_TIME / 8; // next bit slice + + if (TX_BitsRemaining) + { + if (--TX_BitsRemaining != 9) // no start bit + { + if (TX_Data & (1 << 0)) // test inverted data + TCCR2A = (1 << COM2B1); + else + TCCR2A = (1 << COM2B1) | (1 << COM2B0); + + TX_Data >>= 1; // shift zero in from left + } + else + { + TCCR2A = (1 << COM2B1); // START bit + } + } + else if (USBtoUART_Buffer.Count) + { + TX_Data = ~RingBuffer_Remove(&USBtoUART_Buffer); + TX_BitsRemaining = 10; + } +}