main_ezlink.c.svn-base

Si4432-T-B1版本资料.rar

/*
** ============================================================================
**
** FILE
**  main.c
**
** DESCRIPTION
**  This is the main file of the project.	    
**  HW platform EZLink module with C8051F93x Silabs MCU 
**
** CREATED
**  Silicon Laboratories Hungary Ltd
**
** COPYRIGHT
**  Copyright 2009 Silicon Laboratories, Inc.  
**	http://www.silabs.com
**
** ============================================================================
*/


								/* ======================================================== *
								 *									INCLUDE					*
							 	 * ======================================================== */


#include "C8051F930_defs.h"
#include "compiler_defs.h"
#include "string.h"

							/* ================================================================ *
							 * C8051F930 Pin definitions for Software Development Board         *
							 * 					(using compiler_def.h macros) 					*
							 *	=============================================================== */	

SBIT (NSS, SFR_P1, 3);
SBIT (NIRQ, SFR_P0, 6);
SBIT (SDN, SFR_P0, 1);
SBIT (RX_LED, SFR_P2, 0);      
SBIT (TX_LED, SFR_P1, 6);      
SBIT (PB,     SFR_P0, 7);       

								/* ======================================================== *
								 *							Function PROTOTYPES				* 
								 * ======================================================== */
//MCU initialization
void MCU_Init(void);
//SPI functions						
void SpiWriteRegister (U8, U8);
U8 SpiReadRegister (U8);


void main(void)
{
	U8 ItStatus1,ItStatus2;
	U16 delay;
	U8 length,temp8;
	U8 payload[10];

	//Initialize the MCU: 
	//	- set IO ports for the Software Development board
	//	- set MCU clock source
	//	- initialize the SPI port 
	//	- turn ofF LEDs
	MCU_Init();
							/* ======================================================== *
							 *						Initialize the Si4431 ISM chip		* 
							 * ======================================================== */

	//Turn on the radio by pulling down the PWRDN pin
	SDN = 0;
	//Wait at least 15ms befory any initialization SPI commands are sent to the radio
	// (wait for the power on reset sequence) 
	for (temp8=0;temp8<15;temp8++)
	{
		for(delay=0;delay<10000;delay++);
	}	 
			
	//read interrupt status registers to clear the interrupt flags and release NIRQ pin
	ItStatus1 = SpiReadRegister(0x03);															//read the Interrupt Status1 register
	ItStatus2 = SpiReadRegister(0x04);															//read the Interrupt Status2 register
						
	//SW reset   
   	SpiWriteRegister(0x07, 0x80);																//write 0x80 to the Operating & Function Control1 register 
	//wait for chip ready interrupt from the radio (while the nIRQ pin is high)
	while ( NIRQ == 1);  
	//read interrupt status registers to clear the interrupt flags and release NIRQ pin
	ItStatus1 = SpiReadRegister(0x03);															//read the Interrupt Status1 register
	ItStatus2 = SpiReadRegister(0x04);															//read the Interrupt Status2 register
	

							/*set the physical signal parameters*/
	//set the center frequency to 915 MHz
	SpiWriteRegister(0x75, 0x75);																//write 0x73 to the Frequency Band Select register             
   	SpiWriteRegister(0x76, 0xBB);																//write 0xBB to the Nominal Carrier Frequency1 register
   	SpiWriteRegister(0x77, 0x80);  																//write 0x80 to the Nominal Carrier Frequency0 register
	
							/*set the modem parameters according to the exel calculator(parameters: 9.6 kbps, deviation: 45 kHz, channel filter BW: 112.1 kHz*/
	SpiWriteRegister(0x1C, 0x1E);																//write 0x1E to the IF Filter Bandwidth register		
	SpiWriteRegister(0x20, 0xD0);																//write 0xD0 to the Clock Recovery Oversampling Ratio register		
	SpiWriteRegister(0x21, 0x00);																//write 0x00 to the Clock Recovery Offset 2 register		
	SpiWriteRegister(0x22, 0x9D);																//write 0x9D to the Clock Recovery Offset 1 register		
	SpiWriteRegister(0x23, 0x49);																//write 0x49 to the Clock Recovery Offset 0 register		
	SpiWriteRegister(0x24, 0x00);																//write 0x00 to the Clock Recovery Timing Loop Gain 1 register		
	SpiWriteRegister(0x25, 0x24);																//write 0x24 to the Clock Recovery Timing Loop Gain 0 register		
	SpiWriteRegister(0x1D, 0x40);																//write 0x40 to the AFC Loop Gearshift Override register		
	SpiWriteRegister(0x2A, 0x20);																//write 0x20 to the AFC Limiter register		

	//set the Modem test register 
	SpiWriteRegister(0x56, 0xC1);																//write 0xC1 to the Modem test register
											

							/*Configure the receive packet handler*/
	//Disable header bytes; set variable packet length (the length of the payload is defined by the
	//received packet length field of the packet); set the synch word to two bytes long
   	SpiWriteRegister(0x33, 0x02 );																//write 0x02 to the Header Control2 register    
	//Disable the receive header filters
   	SpiWriteRegister(0x32, 0x00 );																//write 0x00 to the Header Control1 register            
	
	//Set the sync word pattern to 0x2DD4
	SpiWriteRegister(0x36, 0x2D);																//write 0x2D to the Sync Word 3 register
	SpiWriteRegister(0x37, 0xD4);																//write 0xD4 to the Sync Word 2 register

	//Enable the receive packet handler and CRC-16 (IBM) check
	SpiWriteRegister(0x30, 0x85);																//write 0x85 to the Data Access Control register
	//Enable FIFO mode and GFSK modulation
	SpiWriteRegister(0x71, 0x63);										 						//write 0x63 to the Modulation Mode Control 2 register
	//set preamble detection threshold to 20bits
	SpiWriteRegister(0x35, 0x2A); 																//write 0x2A to the Preamble Detection Control  register
	//set preamble length to 5bytes
	SpiWriteRegister(0x34, 0x0C);																//write 0x0C to the Preamble Length register

    						/*Set the GPIO's to control the RF switch*/
   	SpiWriteRegister(0x0C, 0x12);																//write 0x12 to the GPIO1 Configuration(set the TX state)
	SpiWriteRegister(0x0D, 0x15);																//write 0x15 to the GPIO2 Configuration(set the RX state) 
	
											/*set the non-default Si4431 registers*/
	//set the VCO and PLL
	SpiWriteRegister(0x57, 0x01);																//write 0x01 to the Chargepump Test register													
	SpiWriteRegister(0x59, 0x00);																//write 0x40 to the Divider Current Trimming register 	
	SpiWriteRegister(0x5A, 0x01); 																//write 0x01 to the VCO Current Trimming register 
	//set  Crystal Oscillator Load Capacitance register
	SpiWriteRegister(0x09, 0xD7);																//write 0xD7 to the Crystal Oscillator Load Capacitance register

    
	/*enable receiver chain*/
	SpiWriteRegister(0x07, 0x05);																//write 0x05 to the Operating Function Control 1 register
	//Enable two interrupts: 
	// a) one wich shows that a valid preamble received:'ipreaval'
	// b) second shows if a sync word received:'iswdet'
	SpiWriteRegister(0x05, 0x00); 																//write 0x00 to the Interrupt Enable 1 register
	SpiWriteRegister(0x06, 0xC0); 																//write 0xC0 to the Interrupt Enable 2 register
	//read interrupt status registers to release all pending interrupts
	ItStatus1 = SpiReadRegister(0x03);															//read the Interrupt Status1 register
	ItStatus2 = SpiReadRegister(0x04);															//read the Interrupt Status2 register

	/*MAIN Loop*/
	while(1)
	{
		//wait for the interrupt event
		if( NIRQ == 0 )
		{
			//read interrupt status registers 
			ItStatus1 = SpiReadRegister(0x03);													//read the Interrupt Status1 register
			ItStatus2 = SpiReadRegister(0x04);													//read the Interrupt Status2 register

			//check whether preamble is detected
			if( (ItStatus2 & 0x40) == 0x40 )
			{//preamble detected
				//wait for the synch word interrupt with timeout -- THIS is the proposed SW workaround
				//start a timer in the MCU and during timeout check whether synch word interrupt happened or not
				delay = 0;
				do {
					delay++;
				} while((delay < 20000) && (NIRQ == 1));	
				
				
				//check whether the synch word interrupt is detected
				if( NIRQ == 0)
				{//synch word detected correctly
					//read interrupt status registers 
					ItStatus1 = SpiReadRegister(0x03);											//read the Interrupt Status1 register
					ItStatus2 = SpiReadRegister(0x04);											//read the Interrupt Status2 register
				
					//Enable two interrupts: 
					// a) one which shows that a valid packet received: 'ipkval'
					// b) second shows if the packet received with incorrect CRC: 'icrcerror' 
					SpiWriteRegister(0x05, 0x03); 												//write 0x03 to the Interrupt Enable 1 register
					SpiWriteRegister(0x06, 0x00); 												//write 0x00 to the Interrupt Enable 2 register
					//read interrupt status registers to release all pending interrupts
					ItStatus1 = SpiReadRegister(0x03);											//read the Interrupt Status1 register
					ItStatus2 = SpiReadRegister(0x04);											//read the Interrupt Status2 register
						
					//wait for the interrupt event
					while(NIRQ == 1);	

				   //read interrupt status registers 
					ItStatus1 = SpiReadRegister(0x03);											//read the Interrupt Status1 register
					ItStatus2 = SpiReadRegister(0x04);											//read the Interrupt Status2 register