Added support to the AVRISP-MKII project for ISP speeds slower than 125KHz via a new software SPI driver.

Added new SPI_ORDER_* data order masks to the SPI peripheral driver.

1 files changed, 171 insertions, 49 deletions

diff --git a/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c b/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c
index 2df8710eb..7c40ff847 100644
--- a/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c
+++ b/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c
@@ -37,7 +37,7 @@
 
 #if defined(ENABLE_ISP_PROTOCOL) || defined(__DOXYGEN__)
 
-/** List of SPI prescaler masks for possible AVRStudio ISP programming speeds. */
+/** List of hardware SPI prescaler masks for possible AVRStudio ISP programming speeds. */
 static uint8_t SPIMaskFromSCKDuration[] PROGMEM =
 {
 #if (F_CPU == 8000000)
@@ -61,25 +61,147 @@ static uint8_t SPIMaskFromSCKDuration[] PROGMEM =
 #endif
 };
 
-/** Converts the given AVR Studio SCK duration parameter (set by a SET PARAM command from the host) to the nearest
- *  possible SPI clock prescaler mask for passing to the SPI_Init() routine.
- *
- *  \return Nearest SPI prescaler mask for the given SCK frequency
+/** Lookup table to convert the slower ISP speeds into a compare value for the software SPI driver. */
+static uint16_t TimerCompareFromSCKDuration[] PROGMEM =
+{
+	TIMER_COMP(96386), TIMER_COMP(89888), TIMER_COMP(84211), TIMER_COMP(79208), TIMER_COMP(74767),
+	TIMER_COMP(70797), TIMER_COMP(67227), TIMER_COMP(64000), TIMER_COMP(61069), TIMER_COMP(58395),
+	TIMER_COMP(55945), TIMER_COMP(51613), TIMER_COMP(49690), TIMER_COMP(47905), TIMER_COMP(46243),
+	TIMER_COMP(43244), TIMER_COMP(41885), TIMER_COMP(39409), TIMER_COMP(38278), TIMER_COMP(36200),
+	TIMER_COMP(34335), TIMER_COMP(32654), TIMER_COMP(31129), TIMER_COMP(29740), TIMER_COMP(28470),
+	TIMER_COMP(27304), TIMER_COMP(25724), TIMER_COMP(24768), TIMER_COMP(23461), TIMER_COMP(22285),
+	TIMER_COMP(21221), TIMER_COMP(20254), TIMER_COMP(19371), TIMER_COMP(18562), TIMER_COMP(17583),
+	TIMER_COMP(16914), TIMER_COMP(16097), TIMER_COMP(15356), TIMER_COMP(14520), TIMER_COMP(13914),
+	TIMER_COMP(13224), TIMER_COMP(12599), TIMER_COMP(12031), TIMER_COMP(11511), TIMER_COMP(10944),
+	TIMER_COMP(10431), TIMER_COMP(9963),  TIMER_COMP(9468),  TIMER_COMP(9081),  TIMER_COMP(8612),
+	TIMER_COMP(8239),  TIMER_COMP(7851),  TIMER_COMP(7498),  TIMER_COMP(7137),  TIMER_COMP(6809),
+	TIMER_COMP(6478),  TIMER_COMP(6178),  TIMER_COMP(5879),  TIMER_COMP(5607),  TIMER_COMP(5359),
+	TIMER_COMP(5093),  TIMER_COMP(4870),  TIMER_COMP(4633),  TIMER_COMP(4418),  TIMER_COMP(4209),
+	TIMER_COMP(4019),  TIMER_COMP(3823),  TIMER_COMP(3645),  TIMER_COMP(3474),  TIMER_COMP(3310),
+	TIMER_COMP(3161),  TIMER_COMP(3011),  TIMER_COMP(2869),  TIMER_COMP(2734),  TIMER_COMP(2611),
+	TIMER_COMP(2484),  TIMER_COMP(2369),  TIMER_COMP(2257),  TIMER_COMP(2152),  TIMER_COMP(2052),
+	TIMER_COMP(1956),  TIMER_COMP(1866),  TIMER_COMP(1779),  TIMER_COMP(1695),  TIMER_COMP(1615),
+	TIMER_COMP(1539),  TIMER_COMP(1468),  TIMER_COMP(1398),  TIMER_COMP(1333),  TIMER_COMP(1271),
+	TIMER_COMP(1212),  TIMER_COMP(1155),  TIMER_COMP(1101),  TIMER_COMP(1049),  TIMER_COMP(1000),
+	TIMER_COMP(953),   TIMER_COMP(909),   TIMER_COMP(866),   TIMER_COMP(826),   TIMER_COMP(787),
+	TIMER_COMP(750),   TIMER_COMP(715),   TIMER_COMP(682),   TIMER_COMP(650),   TIMER_COMP(619),
+	TIMER_COMP(590),   TIMER_COMP(563),   TIMER_COMP(536),   TIMER_COMP(511),   TIMER_COMP(487),
+	TIMER_COMP(465),   TIMER_COMP(443),   TIMER_COMP(422),   TIMER_COMP(402),   TIMER_COMP(384),
+	TIMER_COMP(366),   TIMER_COMP(349),   TIMER_COMP(332),   TIMER_COMP(317),   TIMER_COMP(302),
+	TIMER_COMP(288),   TIMER_COMP(274),   TIMER_COMP(261),   TIMER_COMP(249),   TIMER_COMP(238),
+	TIMER_COMP(226),   TIMER_COMP(216),   TIMER_COMP(206),   TIMER_COMP(196),   TIMER_COMP(187),
+	TIMER_COMP(178),   TIMER_COMP(170),   TIMER_COMP(162),   TIMER_COMP(154),   TIMER_COMP(147),
+	TIMER_COMP(140),   TIMER_COMP(134),   TIMER_COMP(128),   TIMER_COMP(122),   TIMER_COMP(116),
+	TIMER_COMP(111),   TIMER_COMP(105),   TIMER_COMP(100),   TIMER_COMP(95.4),  TIMER_COMP(90.9),
+	TIMER_COMP(86.6),  TIMER_COMP(82.6),  TIMER_COMP(78.7),  TIMER_COMP(75.0),  TIMER_COMP(71.5),
+	TIMER_COMP(68.2),  TIMER_COMP(65.0),  TIMER_COMP(61.9),  TIMER_COMP(59.0),  TIMER_COMP(56.3),
+	TIMER_COMP(53.6),  TIMER_COMP(51.1)
+};
+
+/** Currently selected SPI driver, either hardware (for fast ISP speeds) or software (for slower ISP speeds). */
+bool HardwareSPIMode = true;
+
+/** Software SPI data register for sending and receiving */
+volatile uint8_t SoftSPI_Data;
+
+/** Number of bits left to transfer in the software SPI driver */
+volatile uint8_t SoftSPI_BitsRemaining;
+
+
+/** ISR to handle software SPI transmission and reception */
+ISR(TIMER1_COMPA_vect, ISR_BLOCK)
+{
+	if (!(PINB & (1 << 1)))
+	{
+		if (SoftSPI_Data & 0x80)
+		  PORTB |=  (1 << 2);
+		else
+		  PORTB &= ~(1 << 2);
+	}
+	else
+	{
+		SoftSPI_Data <<= 1;
+
+		if (!(SoftSPI_BitsRemaining--))
+		  TCCR1B = 0;
+
+		if (PINB & (1 << 3))
+		  SoftSPI_Data |= 0x01;	
+	}
+
+	PORTB ^= (1 << 1);	
+}
+
+/** Initializes the appropriate SPI driver (hardware or software, depending on the selected ISP speed) ready for
+ *  communication with the attached target.
  */
-uint8_t ISPTarget_GetSPIPrescalerMask(void)
+void ISPTarget_Init(void)
 {
 	uint8_t SCKDuration = V2Params_GetParameterValue(PARAM_SCK_DURATION);
 
-	if (SCKDuration >= sizeof(SPIMaskFromSCKDuration))
-	  SCKDuration = (sizeof(SPIMaskFromSCKDuration) - 1);
-	  
-	return pgm_read_byte(&SPIMaskFromSCKDuration[SCKDuration]);
+	if (SCKDuration < sizeof(SPIMaskFromSCKDuration))
+	{
+		HardwareSPIMode = true;
+
+		SPI_Init(pgm_read_byte(&SPIMaskFromSCKDuration[SCKDuration]) | SPI_ORDER_MSB_FIRST |
+		                       SPI_SCK_LEAD_RISING | SPI_SAMPLE_LEADING | SPI_MODE_MASTER);
+	}
+	else
+	{
+		HardwareSPIMode = false;
+		
+		DDRB  |= ((1 << 1) | (1 << 2));
+		PORTB |= ((1 << 0) | (1 << 3));
+
+		TIMSK1 = (1 << OCIE1A);
+		OCR1A  = pgm_read_word(&TimerCompareFromSCKDuration[SCKDuration - sizeof(SPIMaskFromSCKDuration)]);
+	}
+}
+
+/** Shuts down the current selected SPI driver (hardware or software, depending on the selected ISP speed) so that no
+ *  further communications can occur until the driver is re-initialized.
+ */
+void ISPTarget_ShutDown(void)
+{
+	if (HardwareSPIMode)
+	{
+		SPI_ShutDown();
+	}
+	else
+	{
+		DDRB  &= ~((1 << 1) | (1 << 2));
+		PORTB &= ~((1 << 0) | (1 << 3));	
+	}
+}
+
+/** Sends and receives a single byte of data to and from the attached target via software SPI.
+ *
+ *  \param[in] Byte  Byte of data to send to the attached target
+ *
+ *  \return Received byte of data from the attached target
+ */
+uint8_t ISPTarget_TransferSoftSPIByte(const uint8_t Byte)
+{
+	SoftSPI_Data          = Byte;
+	SoftSPI_BitsRemaining = 8;
+
+	if (SoftSPI_Data & 0x01)
+	  PORTB |=  (1 << 2);
+	else
+	  PORTB &= ~(1 << 2);
+
+	TCNT1  = 0;
+	TCCR1B = ((1 << WGM12) | (1 << CS11));
+	while (SoftSPI_BitsRemaining && TimeoutTicksRemaining);
+	TCCR1B = 0;
+	
+	return SoftSPI_Data;
 }
 
 /** Asserts or deasserts the target's reset line, using the correct polarity as set by the host using a SET PARAM command.
  *  When not asserted, the line is tristated so as not to interfere with normal device operation.
  *
- *  \param[in] ResetTarget Boolean true when the target should be held in reset, false otherwise
+ *  \param[in] ResetTarget  Boolean true when the target should be held in reset, false otherwise
  */
 void ISPTarget_ChangeTargetResetLine(const bool ResetTarget)
 {
@@ -97,14 +219,44 @@ void ISPTarget_ChangeTargetResetLine(const bool ResetTarget)
 	}
 }
 
+/** Waits until the target has completed the last operation, by continuously polling the device's
+ *  BUSY flag until it is cleared, or until the command timeout period has expired.
+ *
+ *  \return V2 Protocol status \ref STATUS_CMD_OK if the no timeout occurred, \ref STATUS_RDY_BSY_TOUT otherwise
+ */
+uint8_t ISPTarget_WaitWhileTargetBusy(void)
+{
+	do
+	{
+		ISPTarget_SendByte(0xF0);
+		ISPTarget_SendByte(0x00);
+		ISPTarget_SendByte(0x00);
+	}
+	while ((ISPTarget_ReceiveByte() & 0x01) && TimeoutTicksRemaining);
+
+	return TimeoutTicksRemaining ? STATUS_CMD_OK : STATUS_RDY_BSY_TOUT;
+}
+
+/** Sends a low-level LOAD EXTENDED ADDRESS command to the target, for addressing of memory beyond the
+ *  64KB boundary. This sends the command with the correct address as indicated by the current address
+ *  pointer variable set by the host when a SET ADDRESS command is issued.
+ */
+void ISPTarget_LoadExtendedAddress(void)
+{
+	ISPTarget_SendByte(LOAD_EXTENDED_ADDRESS_CMD);
+	ISPTarget_SendByte(0x00);
+	ISPTarget_SendByte((CurrentAddress & 0x00FF0000) >> 16);
+	ISPTarget_SendByte(0x00);	
+}
+
 /** Waits until the last issued target memory programming command has completed, via the check mode given and using
  *  the given parameters.
  *
  *  \param[in] ProgrammingMode  Programming mode used and completion check to use, a mask of PROG_MODE_* constants
- *  \param[in] PollAddress  Memory address to poll for completion if polling check mode used
- *  \param[in] PollValue  Poll value to check against if polling check mode used
- *  \param[in] DelayMS  Milliseconds to delay before returning if delay check mode used
- *  \param[in] ReadMemCommand  Device low-level READ MEMORY command to send if value check mode used
+ *  \param[in] PollAddress      Memory address to poll for completion if polling check mode used
+ *  \param[in] PollValue        Poll value to check against if polling check mode used
+ *  \param[in] DelayMS          Milliseconds to delay before returning if delay check mode used
+ *  \param[in] ReadMemCommand   Device low-level READ MEMORY command to send if value check mode used
  *
  *  \return V2 Protocol status \ref STATUS_CMD_OK if the no timeout occurred, \ref STATUS_RDY_BSY_TOUT or
  *          \ref STATUS_CMD_TOUT otherwise
@@ -128,11 +280,11 @@ uint8_t ISPTarget_WaitForProgComplete(const uint8_t ProgrammingMode,
 		case PROG_MODE_PAGED_VALUE_MASK:
 			do
 			{
-				SPI_SendByte(ReadMemCommand);
-				SPI_SendByte(PollAddress >> 8);
-				SPI_SendByte(PollAddress & 0xFF);
+				ISPTarget_SendByte(ReadMemCommand);
+				ISPTarget_SendByte(PollAddress >> 8);
+				ISPTarget_SendByte(PollAddress & 0xFF);
 			}
-			while ((SPI_TransferByte(0x00) == PollValue) && TimeoutTicksRemaining);
+			while ((ISPTarget_TransferByte(0x00) == PollValue) && TimeoutTicksRemaining);
 
 			if (!(TimeoutTicksRemaining))
 			 ProgrammingStatus = STATUS_CMD_TOUT;
@@ -147,34 +299,4 @@ uint8_t ISPTarget_WaitForProgComplete(const uint8_t ProgrammingMode,
 	return ProgrammingStatus;
 }
 
-/** Waits until the target has completed the last operation, by continuously polling the device's
- *  BUSY flag until it is cleared, or until the command timeout period has expired.
- *
- *  \return V2 Protocol status \ref STATUS_CMD_OK if the no timeout occurred, \ref STATUS_RDY_BSY_TOUT otherwise
- */
-uint8_t ISPTarget_WaitWhileTargetBusy(void)
-{
-	do
-	{
-		SPI_SendByte(0xF0);
-		SPI_SendByte(0x00);
-		SPI_SendByte(0x00);
-	}
-	while ((SPI_ReceiveByte() & 0x01) && TimeoutTicksRemaining);
-
-	return TimeoutTicksRemaining ? STATUS_CMD_OK : STATUS_RDY_BSY_TOUT;
-}
-
-/** Sends a low-level LOAD EXTENDED ADDRESS command to the target, for addressing of memory beyond the
- *  64KB boundary. This sends the command with the correct address as indicated by the current address
- *  pointer variable set by the host when a SET ADDRESS command is issued.
- */
-void ISPTarget_LoadExtendedAddress(void)
-{
-	SPI_SendByte(LOAD_EXTENDED_ADDRESS_CMD);
-	SPI_SendByte(0x00);
-	SPI_SendByte((CurrentAddress & 0x00FF0000) >> 16);
-	SPI_SendByte(0x00);	
-}
-
 #endif