Projects/AVRISP-MKII/Lib/XPROG/XPROGTarget.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Target-related functions for the PDI Protocol decoder.
  34  */
  35
  36 #define  INCLUDE_FROM_XPROGTARGET_C
  37 #include "XPROGTarget.h"
  38
  39 #if defined(ENABLE_XPROG_PROTOCOL) || defined(__DOXYGEN__)
  40
  41 /** Flag to indicate if the USART is currently in Tx or Rx mode. */
  42 bool IsSending;
  43
  44 /** Enables the target's PDI interface, holding the target in reset until PDI mode is exited. */
  45 void XPROGTarget_EnableTargetPDI(void)
  46 {
  47         IsSending = false;
  48
  49         /* Set Tx and XCK as outputs, Rx as input */
  50         DDRD |=  (1 << 5) | (1 << 3);
  51         DDRD &= ~(1 << 2);
  52
  53         /* Set DATA line high for at least 90ns to disable /RESET functionality */
  54         PORTD |= (1 << 3);
  55         _delay_us(1);
  56
  57         /* Set up the synchronous USART for XMEGA communications - 8 data bits, even parity, 2 stop bits */
  58         UBRR1  = ((F_CPU / 2 / XPROG_HARDWARE_SPEED) - 1);
  59         UCSR1B = (1 << TXEN1);
  60         UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
  61
  62         /* Send two IDLEs of 12 bits each to enable PDI interface (need at least 16 idle bits) */
  63         XPROGTarget_SendIdle();
  64         XPROGTarget_SendIdle();
  65 }
  66
  67 /** Enables the target's TPI interface, holding the target in reset until TPI mode is exited. */
  68 void XPROGTarget_EnableTargetTPI(void)
  69 {
  70         IsSending = false;
  71
  72         /* Set /RESET line low for at least 400ns to enable TPI functionality */
  73         AUX_LINE_DDR  |=  AUX_LINE_MASK;
  74         AUX_LINE_PORT &= ~AUX_LINE_MASK;
  75         _delay_us(1);
  76
  77         /* Set Tx and XCK as outputs, Rx as input */
  78         DDRD |=  (1 << 5) | (1 << 3);
  79         DDRD &= ~(1 << 2);
  80
  81         /* Set up the synchronous USART for TINY communications - 8 data bits, even parity, 2 stop bits */
  82         UBRR1  = ((F_CPU / 2 / XPROG_HARDWARE_SPEED) - 1);
  83         UCSR1B = (1 << TXEN1);
  84         UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
  85
  86         /* Send two IDLEs of 12 bits each to enable TPI interface (need at least 16 idle bits) */
  87         XPROGTarget_SendIdle();
  88         XPROGTarget_SendIdle();
  89 }
  90
  91 /** Disables the target's PDI interface, exits programming mode and starts the target's application. */
  92 void XPROGTarget_DisableTargetPDI(void)
  93 {
  94         /* Switch to Rx mode to ensure that all pending transmissions are complete */
  95         XPROGTarget_SetRxMode();
  96
  97         /* Turn off receiver and transmitter of the USART, clear settings */
  98         UCSR1A  = ((1 << TXC1) | (1 << RXC1));
  99         UCSR1B  = 0;
 100         UCSR1C  = 0;
 101
 102         /* Tristate all pins */
 103         DDRD  &= ~((1 << 5) | (1 << 3));
 104         PORTD &= ~((1 << 5) | (1 << 3) | (1 << 2));
 105 }
 106
 107 /** Disables the target's TPI interface, exits programming mode and starts the target's application. */
 108 void XPROGTarget_DisableTargetTPI(void)
 109 {
 110         /* Switch to Rx mode to ensure that all pending transmissions are complete */
 111         XPROGTarget_SetRxMode();
 112
 113         /* Turn off receiver and transmitter of the USART, clear settings */
 114         UCSR1A |= (1 << TXC1) | (1 << RXC1);
 115         UCSR1B  = 0;
 116         UCSR1C  = 0;
 117
 118         /* Set all USART lines as inputs, tristate */
 119         DDRD  &= ~((1 << 5) | (1 << 3));
 120         PORTD &= ~((1 << 5) | (1 << 3) | (1 << 2));
 121
 122         /* Tristate target /RESET line */
 123         AUX_LINE_DDR  &= ~AUX_LINE_MASK;
 124         AUX_LINE_PORT &= ~AUX_LINE_MASK;
 125 }
 126
 127 /** Sends a byte via the USART.
 128  *
 129  *  \param[in] Byte  Byte to send through the USART
 130  */
 131 void XPROGTarget_SendByte(const uint8_t Byte)
 132 {
 133         /* Switch to Tx mode if currently in Rx mode */
 134         if (!(IsSending))
 135           XPROGTarget_SetTxMode();
 136
 137         /* Wait until there is space in the hardware Tx buffer before writing */
 138         while (!(UCSR1A & (1 << UDRE1)));
 139         UCSR1A |= (1 << TXC1);
 140         UDR1    = Byte;
 141 }
 142
 143 /** Receives a byte via the software USART, blocking until data is received.
 144  *
 145  *  \return Received byte from the USART
 146  */
 147 uint8_t XPROGTarget_ReceiveByte(void)
 148 {
 149         /* Switch to Rx mode if currently in Tx mode */
 150         if (IsSending)
 151           XPROGTarget_SetRxMode();
 152
 153         /* Wait until a byte has been received before reading */
 154         while (!(UCSR1A & (1 << RXC1)) && TimeoutTicksRemaining);
 155
 156         return UDR1;
 157 }
 158
 159 /** Sends an IDLE via the USART to the attached target, consisting of a full frame of idle bits. */
 160 void XPROGTarget_SendIdle(void)
 161 {
 162         /* Switch to Tx mode if currently in Rx mode */
 163         if (!(IsSending))
 164           XPROGTarget_SetTxMode();
 165
 166         /* Need to do nothing for a full frame to send an IDLE */
 167         for (uint8_t i = 0; i < BITS_IN_USART_FRAME; i++)
 168         {
 169                 /* Wait for a full cycle of the clock */
 170                 while (PIND & (1 << 5));
 171                 while (!(PIND & (1 << 5)));
 172         }
 173 }
 174
 175 static void XPROGTarget_SetTxMode(void)
 176 {
 177         /* Wait for a full cycle of the clock */
 178         while (PIND & (1 << 5));
 179         while (!(PIND & (1 << 5)));
 180
 181         PORTD  |=  (1 << 3);
 182         DDRD   |=  (1 << 3);
 183
 184         UCSR1B &= ~(1 << RXEN1);
 185         UCSR1B |=  (1 << TXEN1);
 186
 187         IsSending = true;
 188 }
 189
 190 static void XPROGTarget_SetRxMode(void)
 191 {
 192         while (!(UCSR1A & (1 << TXC1)));
 193         UCSR1A |=  (1 << TXC1);
 194
 195         UCSR1B &= ~(1 << TXEN1);
 196         UCSR1B |=  (1 << RXEN1);
 197
 198         DDRD   &= ~(1 << 3);
 199         PORTD  &= ~(1 << 3);
 200
 201         IsSending = false;
 202 }
 203
 204 #endif
 205