Start of implementation of the low level TPI programming protocol in the AVRISP project.

1 files changed, 7 insertions, 8 deletions

diff --git a/Projects/AVRISP/Lib/PDITarget.c b/Projects/AVRISP/Lib/PDITarget.c
index 29bb33985..2c6ffd9a6 100644
--- a/Projects/AVRISP/Lib/PDITarget.c
+++ b/Projects/AVRISP/Lib/PDITarget.c
@@ -67,13 +67,13 @@ ISR(TIMER1_COMPA_vect, ISR_BLOCK)
 		  return;

 		  

 		/* Wait for the start bit when receiving */

-		if ((SoftUSART_BitCount == BITS_IN_FRAME) && (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK))

+		if ((SoftUSART_BitCount == BITS_IN_PDI_FRAME) && (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK))

 		  return;

 	

 		/* Shift in the bit one less than the frame size in position, so that the start bit will eventually

 		 * be discarded leaving the data to be byte-aligned for quick access */

 		if (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK)

-		  SoftUSART_Data |= (1 << (BITS_IN_FRAME - 1));

+		  SoftUSART_Data |= (1 << (BITS_IN_PDI_FRAME - 1));

 

 		SoftUSART_Data >>= 1;

 		SoftUSART_BitCount--;

@@ -133,6 +133,7 @@ void PDITarget_EnableTargetPDI(void)
 	TCCR1B  = (1 << WGM12) | (1 << CS10);

 	TIMSK1  = (1 << OCIE1A);

 	

+	/* Send two BREAKs of 12 bits each to enable TPI interface (need at least 16 idle bits) */

 	PDITarget_SendBreak();

 	PDITarget_SendBreak();

 #endif

@@ -158,8 +159,6 @@ void PDITarget_DisableTargetPDI(void)
 	/* Tristate DATA and CLOCK lines */

 	BITBANG_PDIDATA_PORT  &= ~BITBANG_PDIDATA_MASK;

 	BITBANG_PDICLOCK_PORT &= ~BITBANG_PDICLOCK_MASK;

-

-	TCCR0B  = 0;

 #endif

 }

 

@@ -212,7 +211,7 @@ void PDITarget_SendByte(const uint8_t Byte)
 

 	/* Data shifted out LSB first, START DATA PARITY STOP STOP */

 	SoftUSART_Data     = NewUSARTData;

-	SoftUSART_BitCount = BITS_IN_FRAME;

+	SoftUSART_BitCount = BITS_IN_PDI_FRAME;

 #endif

 }

 

@@ -254,7 +253,7 @@ uint8_t PDITarget_ReceiveByte(void)
 	}

 

 	/* Wait until a byte has been received before reading */

-	SoftUSART_BitCount = BITS_IN_FRAME;

+	SoftUSART_BitCount = BITS_IN_PDI_FRAME;

 	while (SoftUSART_BitCount);

 	

 	/* Throw away the parity and stop bits to leave only the data (start bit is already discarded) */

@@ -279,7 +278,7 @@ void PDITarget_SendBreak(void)
 	}

 

 	/* Need to do nothing for a full frame to send a BREAK */

-	for (uint8_t i = 0; i < BITS_IN_FRAME; i++)

+	for (uint8_t i = 0; i < BITS_IN_PDI_FRAME; i++)

 	{

 		/* Wait for a full cycle of the clock */

 		while (PIND & (1 << 5));

@@ -299,7 +298,7 @@ void PDITarget_SendBreak(void)
 

 	/* Need to do nothing for a full frame to send a BREAK */

 	SoftUSART_Data     = 0x0FFF;

-	SoftUSART_BitCount = BITS_IN_FRAME;

+	SoftUSART_BitCount = BITS_IN_PDI_FRAME;

 #endif

 }