X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/60fd0ff418566d85224f9841037ba01b77acc0d8..aca7863350509a1f390eda93ac0150378d8cd16c:/Projects/AVRISP-MKII/Lib/ISP/ISPProtocol.c

diff --git a/Projects/AVRISP-MKII/Lib/ISP/ISPProtocol.c b/Projects/AVRISP-MKII/Lib/ISP/ISPProtocol.c
index 59a77e575..85b31fbdb 100644
--- a/Projects/AVRISP-MKII/Lib/ISP/ISPProtocol.c
+++ b/Projects/AVRISP-MKII/Lib/ISP/ISPProtocol.c
@@ -62,13 +62,20 @@ void ISPProtocol_EnterISPMode(void)
 	uint8_t ResponseStatus = STATUS_CMD_FAILED;
 	
 	CurrentAddress = 0;
+	
+	/* Set up the synchronous USART to generate the recovery clock on XCK pin */
+	UBRR1  = (F_CPU / 500000UL);
+	UCSR1B = (1 << TXEN1);
+	UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
+	DDRD  |= (1 << 5);
 
+	/* Perform execution delay, initialize SPI bus */
 	ISPProtocol_DelayMS(Enter_ISP_Params.ExecutionDelayMS); 
 	SPI_Init(ISPTarget_GetSPIPrescalerMask() | SPI_SCK_LEAD_RISING | SPI_SAMPLE_LEADING | SPI_MODE_MASTER);
 
 	/* Continuously attempt to synchronize with the target until either the number of attempts specified
 	 * by the host has exceeded, or the the device sends back the expected response values */
-	while (Enter_ISP_Params.SynchLoops-- && (ResponseStatus == STATUS_CMD_FAILED))
+	while (Enter_ISP_Params.SynchLoops-- && (ResponseStatus == STATUS_CMD_FAILED) && TimeoutMSRemaining)
 	{
 		uint8_t ResponseBytes[4];
 
@@ -118,6 +125,12 @@ void ISPProtocol_LeaveISPMode(void)
 	SPI_ShutDown();
 	ISPProtocol_DelayMS(Leave_ISP_Params.PostDelayMS);
 
+	/* Turn off the synchronous USART to terminate the recovery clock on XCK pin */
+	UBRR1  = (F_CPU / 500000UL);
+	UCSR1B = (1 << TXEN1);
+	UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
+	DDRD  &= ~(1 << 5);
+
 	Endpoint_Write_Byte(CMD_LEAVE_PROGMODE_ISP);
 	Endpoint_Write_Byte(STATUS_CMD_OK);
 	Endpoint_ClearIN();
@@ -198,14 +211,15 @@ void ISPProtocol_ProgramMemory(uint8_t V2Command)
 			
 			/* AVR FLASH addressing requires us to modify the write command based on if we are writing a high
 			 * or low byte at the current word address */
-			Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
+			if (V2Command == CMD_PROGRAM_FLASH_ISP)
+			  Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
 
 			/* Check to see the write completion method, to see if we have a valid polling address */
 			if (!(PollAddress) && (ByteToWrite != PollValue))
 			{
 				if (IsOddByte && (V2Command == CMD_PROGRAM_FLASH_ISP))
 				  Write_Memory_Params.ProgrammingCommands[2] |= READ_WRITE_HIGH_BYTE_MASK;
-				  
+
 				PollAddress = (CurrentAddress & 0xFFFF);				
 			}		
 
@@ -239,17 +253,17 @@ void ISPProtocol_ProgramMemory(uint8_t V2Command)
 		{
 			bool    IsOddByte   = (CurrentByte & 0x01);
 			uint8_t ByteToWrite = *(NextWriteByte++);
-		
-			if (IsOddByte && (V2Command == CMD_READ_FLASH_ISP))
-			  Write_Memory_Params.ProgrammingCommands[0] |=  READ_WRITE_HIGH_BYTE_MASK;
-			else
-			  Write_Memory_Params.ProgrammingCommands[0] &= ~READ_WRITE_HIGH_BYTE_MASK;			
 			  
 			SPI_SendByte(Write_Memory_Params.ProgrammingCommands[0]);
 			SPI_SendByte(CurrentAddress >> 8);
 			SPI_SendByte(CurrentAddress & 0xFF);
 			SPI_SendByte(ByteToWrite);
 			
+			/* AVR FLASH addressing requires us to modify the write command based on if we are writing a high
+			 * or low byte at the current word address */
+			if (V2Command == CMD_PROGRAM_FLASH_ISP)
+			  Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
+
 			if (ByteToWrite != PollValue)
 			{
 				if (IsOddByte && (V2Command == CMD_PROGRAM_FLASH_ISP))
@@ -504,4 +518,19 @@ void ISPProtocol_SPIMulti(void)
 	}
 }
 
+/** Blocking delay for a given number of milliseconds.
+ *
+ *  \param[in] DelayMS  Number of milliseconds to delay for
+ */
+void ISPProtocol_DelayMS(uint8_t DelayMS)
+{
+	while (DelayMS-- && TimeoutMSRemaining)
+	{
+		if (TimeoutMSRemaining)
+		  TimeoutMSRemaining--;
+		  
+		_delay_ms(1);
+	}
+}
+
 #endif
\ No newline at end of file