Projects/AVRISP/Lib/PDITarget.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, and distribute this software
  13   and its documentation for any purpose and without fee is hereby
  14   granted, provided that the above copyright notice appear in all
  15   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_PDITARGET_C
  37 #include "PDITarget.h"
  38
  39 #if defined(ENABLE_PDI_PROTOCOL) || defined(__DOXYGEN__)
  40
  41 /** Flag to indicate if the USART is currently in Tx or Rx mode. */
  42 volatile bool               IsSending;
  43
  44 #if !defined(PDI_VIA_HARDWARE_USART)
  45 /** Software USART raw frame bits for transmission/reception. */
  46 volatile uint16_t           SoftUSART_Data;
  47
  48 /** Bits remaining to be sent or received via the software USART - set as a GPIOR for speed. */
  49 #define SoftUSART_BitCount  GPIOR2
  50
  51
  52 /** ISR to manage the software USART when bit-banged USART mode is selected. */
  53 ISR(TIMER1_COMPA_vect, ISR_BLOCK)
  54 {
  55         /* Toggle CLOCK pin in a single cycle (see AVR datasheet) */
  56         BITBANG_PDICLOCK_PIN |= BITBANG_PDICLOCK_MASK;
  57
  58         /* If not sending or receiving, just exit */
  59         if (!(SoftUSART_BitCount))
  60           return;
  61
  62         /* Check to see if we are at a rising or falling edge of the clock */
  63         if (BITBANG_PDICLOCK_PORT & BITBANG_PDICLOCK_MASK)
  64         {
  65                 /* If at rising clock edge and we are in send mode, abort */
  66                 if (IsSending)
  67                   return;
  68
  69                 /* Wait for the start bit when receiving */
  70                 if ((SoftUSART_BitCount == BITS_IN_FRAME) && (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK))
  71                   return;
  72
  73                 /* Shift in the bit one less than the frame size in position, so that the start bit will eventually
  74                  * be discarded leaving the data to be byte-aligned for quick access */
  75                 if (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK)
  76                   SoftUSART_Data |= (1 << (BITS_IN_FRAME - 1));
  77
  78                 SoftUSART_Data >>= 1;
  79                 SoftUSART_BitCount--;
  80         }
  81         else
  82         {
  83                 /* If at falling clock edge and we are in receive mode, abort */
  84                 if (!IsSending)
  85                   return;
  86
  87                 /* Set the data line to the next bit value */
  88                 if (SoftUSART_Data & 0x01)
  89                   BITBANG_PDIDATA_PORT |=  BITBANG_PDIDATA_MASK;
  90                 else
  91                   BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;
  92
  93                 SoftUSART_Data >>= 1;
  94                 SoftUSART_BitCount--;
  95         }
  96 }
  97 #endif
  98
  99 /** Enables the target's PDI interface, holding the target in reset until PDI mode is exited. */
 100 void PDITarget_EnableTargetPDI(void)
 101 {
 102 #if defined(PDI_VIA_HARDWARE_USART)
 103         /* Set Tx and XCK as outputs, Rx as input */
 104         DDRD |=  (1 << 5) | (1 << 3);
 105         DDRD &= ~(1 << 2);
 106
 107         /* Set DATA line high for at least 90ns to disable /RESET functionality */
 108         PORTD |= (1 << 3);
 109         asm volatile ("NOP"::);
 110         asm volatile ("NOP"::);
 111
 112         /* Set up the synchronous USART for XMEGA communications -
 113            8 data bits, even parity, 2 stop bits */
 114         UBRR1  = (F_CPU / 1000000UL);
 115         UCSR1B = (1 << TXEN1);
 116         UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
 117
 118         /* Send two BREAKs of 12 bits each to enable PDI interface (need at least 16 idle bits) */
 119         PDITarget_SendBreak();
 120         PDITarget_SendBreak();
 121 #else
 122         /* Set DATA and CLOCK lines to outputs */
 123         BITBANG_PDIDATA_DDR  |= BITBANG_PDIDATA_MASK;
 124         BITBANG_PDICLOCK_DDR |= BITBANG_PDICLOCK_MASK;
 125
 126         /* Set DATA line high for at least 90ns to disable /RESET functionality */
 127         BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
 128         asm volatile ("NOP"::);
 129         asm volatile ("NOP"::);
 130
 131         /* Fire timer compare ISR every 100 cycles to manage the software USART */
 132         OCR1A   = 80;
 133         TCCR1B  = (1 << WGM12) | (1 << CS10);
 134         TIMSK1  = (1 << OCIE1A);
 135
 136         PDITarget_SendBreak();
 137         PDITarget_SendBreak();
 138 #endif
 139 }
 140
 141 /** Disables the target's PDI interface, exits programming mode and starts the target's application. */
 142 void PDITarget_DisableTargetPDI(void)
 143 {
 144 #if defined(PDI_VIA_HARDWARE_USART)
 145         /* Turn off receiver and transmitter of the USART, clear settings */
 146         UCSR1A |= (1 << TXC1) | (1 << RXC1);
 147         UCSR1B  = 0;
 148         UCSR1C  = 0;
 149
 150         /* Set all USART lines as input, tristate */
 151         DDRD  &= ~((1 << 5) | (1 << 3));
 152         PORTD &= ~((1 << 5) | (1 << 3) | (1 << 2));
 153 #else
 154         /* Set DATA and CLOCK lines to inputs */
 155         BITBANG_PDIDATA_DDR   &= ~BITBANG_PDIDATA_MASK;
 156         BITBANG_PDICLOCK_DDR  &= ~BITBANG_PDICLOCK_MASK;
 157
 158         /* Tristate DATA and CLOCK lines */
 159         BITBANG_PDIDATA_PORT  &= ~BITBANG_PDIDATA_MASK;
 160         BITBANG_PDICLOCK_PORT &= ~BITBANG_PDICLOCK_MASK;
 161
 162         TCCR0B  = 0;
 163 #endif
 164 }
 165
 166 /** Sends a byte via the USART.
 167  *
 168  *  \param[in] Byte  Byte to send through the USART
 169  */
 170 void PDITarget_SendByte(uint8_t Byte)
 171 {
 172 #if defined(PDI_VIA_HARDWARE_USART)
 173         /* Switch to Tx mode if currently in Rx mode */
 174         if (!(IsSending))
 175         {
 176                 PORTD  |=  (1 << 3);
 177                 DDRD   |=  (1 << 3);
 178
 179                 UCSR1B |=  (1 << TXEN1);
 180                 UCSR1B &= ~(1 << RXEN1);
 181
 182                 IsSending = true;
 183         }
 184
 185         /* Wait until there is space in the hardware Tx buffer before writing */
 186         while (!(UCSR1A & (1 << UDRE1)));
 187         UCSR1A |= (1 << TXC1);
 188         UDR1    = Byte;
 189 #else
 190         /* Switch to Tx mode if currently in Rx mode */
 191         if (!(IsSending))
 192         {
 193                 BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
 194                 BITBANG_PDIDATA_DDR  |= BITBANG_PDIDATA_MASK;
 195
 196                 IsSending = true;
 197         }
 198
 199         bool    EvenParityBit = false;
 200         uint8_t ParityData    = Byte;
 201
 202         /* Compute Even parity - while a bit is still set, chop off lowest bit and toggle parity bit */
 203         while (ParityData)
 204         {
 205                 EvenParityBit ^= true;
 206                 ParityData    &= (ParityData - 1);
 207         }
 208
 209         /* Calculate the new USART frame data here while while we wait for a previous byte (if any) to finish sending */
 210         uint16_t NewUSARTData = ((1 << 11) | (1 << 10) | ((uint16_t)EvenParityBit << 9) | ((uint16_t)Byte << 1) | (0 << 0));
 211
 212         while (SoftUSART_BitCount);
 213
 214         /* Data shifted out LSB first, START DATA PARITY STOP STOP */
 215         SoftUSART_Data     = NewUSARTData;
 216         SoftUSART_BitCount = BITS_IN_FRAME;
 217 #endif
 218 }
 219
 220 /** Receives a byte via the software USART, blocking until data is received.
 221  *
 222  *  \return Received byte from the USART
 223  */
 224 uint8_t PDITarget_ReceiveByte(void)
 225 {
 226 #if defined(PDI_VIA_HARDWARE_USART)
 227         /* Switch to Rx mode if currently in Tx mode */
 228         if (IsSending)
 229         {
 230                 while (!(UCSR1A & (1 << TXC1)));
 231                 UCSR1A |=  (1 << TXC1);
 232
 233                 UCSR1B &= ~(1 << TXEN1);
 234                 UCSR1B |=  (1 << RXEN1);
 235
 236                 DDRD   &= ~(1 << 3);
 237                 PORTD  &= ~(1 << 3);
 238
 239                 IsSending = false;
 240         }
 241
 242         /* Wait until a byte has been received before reading */
 243         while (!(UCSR1A & (1 << RXC1)));
 244         return UDR1;
 245 #else
 246         /* Switch to Rx mode if currently in Tx mode */
 247         if (IsSending)
 248         {
 249                 while (SoftUSART_BitCount);
 250
 251                 BITBANG_PDIDATA_DDR  &= ~BITBANG_PDIDATA_MASK;
 252                 BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;
 253
 254                 IsSending = false;
 255         }
 256
 257         /* Wait until a byte has been received before reading */
 258         SoftUSART_BitCount = BITS_IN_FRAME;
 259         while (SoftUSART_BitCount);
 260
 261         /* Throw away the start, parity and stop bits to leave only the data */
 262         return (uint8_t)SoftUSART_Data;
 263 #endif
 264 }
 265
 266 /** Sends a BREAK via the USART to the attached target, consisting of a full frame of idle bits. */
 267 void PDITarget_SendBreak(void)
 268 {
 269 #if defined(PDI_VIA_HARDWARE_USART)
 270         /* Switch to Tx mode if currently in Rx mode */
 271         if (!(IsSending))
 272         {
 273                 PORTD  |=  (1 << 3);
 274                 DDRD   |=  (1 << 3);
 275
 276                 UCSR1B &= ~(1 << RXEN1);
 277                 UCSR1B |=  (1 << TXEN1);
 278
 279                 IsSending = true;
 280         }
 281
 282         /* Need to do nothing for a full frame to send a BREAK */
 283         for (uint8_t i = 0; i <= BITS_IN_FRAME; i++)
 284         {
 285                 /* Wait for a full cycle of the clock */
 286                 while (PIND & (1 << 5));
 287                 while (!(PIND & (1 << 5)));
 288         }
 289 #else
 290         /* Switch to Tx mode if currently in Rx mode */
 291         if (!(IsSending))
 292         {
 293                 BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;
 294                 BITBANG_PDIDATA_DDR  |= BITBANG_PDIDATA_MASK;
 295
 296                 IsSending = true;
 297         }
 298
 299         while (SoftUSART_BitCount);
 300
 301         /* Need to do nothing for a full frame to send a BREAK */
 302         SoftUSART_Data     = 0x0FFF;
 303         SoftUSART_BitCount = BITS_IN_FRAME;
 304 #endif
 305 }
 306
 307 /** Busy-waits while the NVM controller is busy performing a NVM operation, such as a FLASH page read or CRC
 308  *  calculation.
 309  *
 310  *  \return Boolean true if the NVM controller became ready within the timeout period, false otherwise
 311  */
 312 bool PDITarget_WaitWhileNVMBusBusy(void)
 313 {
 314         TCNT0 = 0;
 315
 316         /* Poll the STATUS register to check to see if NVM access has been enabled */
 317         while (TCNT0 < PDI_NVM_TIMEOUT_MS)
 318         {
 319                 /* Send the LDCS command to read the PDI STATUS register to see the NVM bus is active */
 320                 PDITarget_SendByte(PDI_CMD_LDCS | PDI_STATUS_REG);
 321                 if (PDITarget_ReceiveByte() & PDI_STATUS_NVM)
 322                   return true;
 323         }
 324
 325         return false;
 326 }
 327
 328 #endif