spi.c

this the firmware provided freely for the trf7960

 =======================================================================================================================
 */

void InitialSettings(void)
{
	/*~~~~~~~~~~~~~~~~~~~~~~~*/
	unsigned char	command[2];
	/*~~~~~~~~~~~~~~~~~~~~~~~*/

	command[0] = ModulatorControl;
	command[1] = 0x21;
	WriteSingle(command, 2);
}

/*
 =======================================================================================================================
 =======================================================================================================================
 */
void InterruptHandlerReader(unsigned char *Register)
{
	/*~~~~~~~~~~~~~~~~*/
	/*
	 * char phello[20];
	 * //for testing
	 */
	unsigned char	len;
	/*~~~~~~~~~~~~~~~~*/

	/*
	 * Register = Register & 0xF7;
	 * //set the parity flag to 0 ;
	 * parity is not used in 15693 and Tag-It
	 */
#if DBG
	Put_byte(*Register);
#endif
	if(*Register == 0xA0)
	{					/* TX active and only 3 bytes left in FIFO */
		i_reg = 0x00;
#if DBG
		kputchar('.');	/* FIFO filling is done in the transmit function */
#endif
	}
	else if(*Register == BIT7)
	{					/* TX complete */
		i_reg = 0x00;
		*Register = Reset;			/* reset the FIFO after TX */
		DirectCommand(Register);
#if DBG
		kputchar('T');
#endif
	}
	else if((*Register & BIT1) == BIT1)
	{								/* collision error */
		i_reg = 0x02;				/* RX complete */

		*Register = StopDecoders;	/* reset the FIFO after TX */
		DirectCommand(Register);

		CollPoss = CollisionPosition;
		ReadSingle(&CollPoss, 1);

		/*
		 * CollPoss &= 0xF7;
		 */
		len = CollPoss - 0x20;		/* number of valid bytes if FIFO */

		if(!POLLING)
		{
			kputchar('{');
			Put_byte(CollPoss);
			kputchar('}');
		}

		if((len & 0x0f) != 0x00) len = len + 0x10;	/* add 1 byte if broken byte recieved */
		len = len >> 4;

		if(len != 0x00)
		{
			buf[RXTXstate] = FIFO;					/* write the recieved bytes to the correct place of the
													 * buffer;
													 * */
			ReadCont(&buf[RXTXstate], len);
			RXTXstate = RXTXstate + len;
		}						/* if */

		*Register = Reset;
		DirectCommand(Register);

		*Register = IRQStatus;	/* IRQ status register address */
		ReadSingle(Register, 1);	/* function call for single address read */
		irqCLR;
	}
	else if(*Register == BIT6)
	{	/* RX flag means that EOF has been recieved */
		/* and the number of unread bytes is in FIFOstatus regiter */
		if(RXErrorFlag == 0x02)
		{
			i_reg = 0x02;
			return;
		}

		*Register = FIFOStatus;
		ReadSingle(Register, 1);					/* determine the number of bytes left in FIFO */
		*Register = (0x0F &*Register) + 0x01;
		buf[RXTXstate] = FIFO;						/* write the recieved bytes to the correct place of the
													 * buffer;
													 * */
		ReadCont(&buf[RXTXstate], *Register);
		RXTXstate = RXTXstate +*Register;

		*Register = TXLenghtByte2;					/* determine if there are broken bytes */
		ReadSingle(Register, 1);					/* determine the number of bits */
		if((*Register & BIT0) == BIT0)
		{
			*Register = (*Register >> 1) & 0x07;	/* mask the first 5 bits */
			*Register = 8 -*Register;
			buf[RXTXstate - 1] &= 0xFF << *Register;
		}								/* if */

#if DBG
		kputchar('E');
#endif
		*Register = Reset;				/* reset the FIFO after last byte has been read out */
		DirectCommand(Register);

		i_reg = 0xFF;					/* signal to the recieve funnction that this are the last bytes */
	}
	else if(*Register == 0x60)
	{									/* RX active and 9 bytes allready in FIFO */
		i_reg = 0x01;
		buf[RXTXstate] = FIFO;
		ReadCont(&buf[RXTXstate], 9);	/* read 9 bytes from FIFO */
		RXTXstate = RXTXstate + 9;
#if DBG
		kputchar('F');
#endif
		if(irqPORT & irqPIN)
		{
			*Register = IRQStatus;		/* IRQ status register address */
			ReadSingle(Register, 1);	/* function call for single address read */
			irqCLR;

			if(*Register == 0x40)
			{	/* end of recieve */
				*Register = FIFOStatus;
				ReadSingle(Register, 1);					/* determine the number of bytes left in FIFO */
				*Register = 0x0F & (*Register + 0x01);
				buf[RXTXstate] = FIFO;						/* write the recieved bytes to the correct place of the
															 * buffer;
															 * */
				ReadCont(&buf[RXTXstate], *Register);
				RXTXstate = RXTXstate +*Register;

				*Register = TXLenghtByte2;					/* determine if there are broken bytes */
				ReadSingle(Register, 1);					/* determine the number of bits */

				if((*Register & BIT0) == BIT0)
				{
					*Register = (*Register >> 1) & 0x07;	/* mask the first 5 bits */
					*Register = 8 -*Register;
					buf[RXTXstate - 1] &= 0xFF << *Register;
				}						/* if */

#if DBG
				kputchar('E');
#endif
				i_reg = 0xFF;			/* signal to the recieve funnction that this are the last bytes */
				*Register = Reset;		/* reset the FIFO after last byte has been read out */
				DirectCommand(Register);
			}
			else if(*Register == 0x50)
			{							/* end of recieve and error */
				i_reg = 0x02;
#if DBG
				kputchar('x');
#endif
			}
		}
		else
		{
			Register[0] = IRQStatus;
			ReadSingle(Register, 2);	/* function call for single address read */
			if(Register[0] == 0x00) i_reg = 0xFF;
		}
	}
	else if((*Register & BIT4) == BIT4)
	{						/* CRC error */
		if((*Register & BIT5) == BIT5)
		{
			i_reg = 0x01;	/* RX active */
			RXErrorFlag = 0x02;
		}
		else
			i_reg = 0x02;	/* end of RX */
	}
	else if((*Register & BIT2) == BIT2)
	{						/* byte framing error */
		if((*Register & BIT5) == BIT5)
		{
			i_reg = 0x01;	/* RX active */
			RXErrorFlag = 0x02;
		}
		else
			i_reg = 0x02;	/* end of RX */
	}
	else if(*Register == BIT0)
	{						/* No response interrupt */
		i_reg = 0x00;
#if DBG
		kputchar('N');
#endif
	}
	else
	{						/* Interrupt register not properly set */
		if(!POLLING)
		{
			/*
			 * sprintf(phello, "Interrupt error. %x\n\r", *Register);
			 * *send_cstring(phello);
			 */
			send_cstring("Interrupt error");
			Put_byte(*Register);
		}

		i_reg = 0x02;

		*Register = StopDecoders;	/* reset the FIFO after TX */
		DirectCommand(Register);

		*Register = Reset;
		DirectCommand(Register);

		*Register = IRQStatus;		/* IRQ status register address */
		ReadSingle(Register, 1);	/* function call for single address read */
		irqCLR;
	}
}	/* InterruptHandlerReader */

/*
 =======================================================================================================================
 =======================================================================================================================
 */

#pragma vector = PORT1_VECTOR
__interrupt void Port_B (void)		/* interrupt handler */
{
	unsigned char Register[2];

	stopCounter;					/* stop timer mode */

	do
	{
		irqCLR;						/* PORT2 interrupt flag clear */
		Register[0] = IRQStatus;	/* IRQ status register address */

		ReadSingle(Register, 1);	/* function call for single address read */

		/* IRQ status register has to be read */
		if(*Register == 0xA0)
		{	/* TX active and only 3 bytes left in FIFO */
			goto FINISH;
		}
		InterruptHandlerReader(&Register[0]);
	} while((irqPORT & irqPIN) == irqPIN);
FINISH:
	__low_power_mode_off_on_exit();
}


// === Modifications====================================================
// 10/30/06 Aarthi Created a new function HostCommands() - Moved the 
//                 while(1) loop from function main() to HostCommands().
// 10/30/06 Aarthi Lines 351, 499 - Added condition to check if program
//                 execution is in polling loop. This is needed to avoid
//                 communication to the USB-UART converter before the
//                 GUI is invoked. 
// 11/01/06 Aarthi Lines 272, 505 - Replaced sprintf with alternate
//                 function to reduce code size.
// =====================================================================