io3w.c

美国模拟混合器件领导厂商Silabs 芯科实验室 收音机系列 源码

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <c8051f320.h>        
#include <stddef.h>       
#include "typedefs.h"

//-----------------------------------------------------------------------------
// Defines
//-----------------------------------------------------------------------------
#define READ	1
#define WRITE	0

//-----------------------------------------------------------------------------
// Global variables
//-----------------------------------------------------------------------------
sbit RSTB     = P1^3;
sbit SENB     = P1^2;
sbit SCLK     = P1^1;
sbit SDIO     = P0^7;


//-----------------------------------------------------------------------------
// Function prototypes
//-----------------------------------------------------------------------------

void wait_ns(u16 ns);
void _nop_(void);


//-----------------------------------------------------------------------------
// Externals
//-----------------------------------------------------------------------------








//-----------------------------------------------------------------------------
// This routine transfers 2 bytes of data between the host and si470x.
//
// Inputs:
//		operation:  Specifies read or write operation
//		addr:		Address for register read or write
//		reg_array:	source array for data to be written
//      					or
//					destination array for data to be read
//
//-----------------------------------------------------------------------------
static void io3w_operation (u8 operation, u8 addr, u16 *reg_array) 
{
	i8 i;
	u16 controlWord;

	P0MDOUT |= 0x80;						// Configure P0^7(SDIO) as push-pull

	// issue the control word (8 bit chip address + R/W* bit)
	if (operation == READ) 
		controlWord = 0x00E0 + addr;		// A7-A5, R/W*, A4-A0
	else 
		controlWord = 0x00C0 + addr;		// // A7-A5, R/W*, A4-A0

	SENB = 0;
	for (i=8; i>=0; i--) 
	{
		SCLK = 0;
		SDIO = ((controlWord >> i) & 0x01);
		wait_ns(25);					// tLOW
		SCLK = 1;
		wait_ns(25);					// tHIGH
	}

	// read or write data
	if (operation == READ) 
	{	   
		P0MDOUT &=  ~(0x80);				// Configure P0^7(SDIO) as open-drain
		SDIO = 1;							// Configure P0^7(SDIO) as a digital input
		
		for (i=15; i>=0; i--) 
		{
			SCLK = 0;
			wait_ns(25);				// tLOW
			SCLK = 1;
			wait_ns(25);				// tCDV
			reg_array[addr] = ((reg_array[addr] << 1) | SDIO);
		}
	}

	if (operation == WRITE)
	{
		for (i=15; i>=0; i--) 
		{
			SCLK = 0;
			SDIO = ((reg_array[addr] >> i) & 0x01);
			wait_ns(25);				// tLOW
			SCLK = 1;
			wait_ns(25);				// tHIGH
		}
	}

	// end the transaction
	SCLK = 0;
	wait_ns(5);							// tLOW - tS
	SENB = 1;
	wait_ns(20);						// tS
	SCLK = 1;
	wait_ns(25);						// tHIGH
	SCLK = 0;
	
	P0MDOUT |= 0x80;					// Configure P0^7(SDIO) as push-pull
	SDIO = 1;												
}


//-----------------------------------------------------------------------------
// This routine reads a block of registers from the Si470x.
//
// Inputs:
//		firstreg:	First register to be read
//		lastreg:	Last register to be read
//		reg_array:	Destination array for data read
//
//-----------------------------------------------------------------------------
void io3w_read (u8 firstreg, u8 lastreg, u16 *reg_array)
{
	u8 reg;
	
	reg = firstreg;
    lastreg = (lastreg+1)& 0xf;

	do
	{
		io3w_operation(READ, reg, reg_array);
		reg = (reg + 1) & 0xf;
    } while (reg != lastreg);
	
}


//-----------------------------------------------------------------------------
// This routine writes a block of registers to the Si470x.
//
// Inputs:
//		firstreg:	First register to be written
//		lastreg:	Last register to be written
//		reg_array:	Source array for data to be written
//
//-----------------------------------------------------------------------------
void io3w_write (u8 firstreg, u8 lastreg, u16 *reg_array)
{
	u8 reg;
	
	reg = firstreg;
    lastreg = (lastreg+1)& 0xf;
    
    do
	{
		io3w_operation(WRITE, reg, reg_array);
		reg = (reg + 1) & 0xf;
    } while (reg != lastreg);
	
}