si470x_low.c

来自「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」· C语言 代码 · 共 116 行

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

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

#define IO3W	0
#define IO2W	1

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

u16 xdata si470x_shadow[16];

u8 io_mode = IO2W;           

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

void io2w_write (u8 lastreg, u16 *reg_array); 
void io2w_read  (u8 lastreg, u16 *reg_array); 
void io3w_write (u8 firstreg, u8 lastreg, u16 *reg_array);
void io3w_read  (u8 firstreg, u8 lastreg, u16 *reg_array);
void wait_ns(u16 ns);
void _nop_(void);


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



//-----------------------------------------------------------------------------
//
//-----------------------------------------------------------------------------
void si470x_reset (void)
{
	// default conditions
	SCLK = 1;
	P0MDOUT = P0MDOUT | 0x80;	// Configure P0^7(SDIO) as push-pull
	SENB = (io_mode == IO2W) ? 1 : 0;		// 0 = 3-wire, 1 = 2-wire
	SDIO = 0;

	// initialization
	RSTB = 0;
	wait_ns(30); 				// tSRST
	RSTB = 1;
	wait_ns(30);				// tHRST

	// default conditions
	SENB = 1;
	P0MDOUT &=  ~(0x80);		// Configure P0^7(SDIO) as open-drain
	SDIO = 1;					// Configure P0^7(SDIO) as a digital input
}


//-----------------------------------------------------------------------------
// Put the Si470x in powerdown mode.  Set the disable bit in register 2, but
// bypass the shadow registers.  This makes it easier to restore register 2
// during powerup.
// 
//-----------------------------------------------------------------------------
void si470x_powerdown (void) {
    u16 powerdown_val[3] = {0, 0, 0x0041}; // DISABLE = 1, ENABLE = 1
    
    if (io_mode == IO3W) {
        io3w_write(2, 2, powerdown_val);
    } else {
        io2w_write(2, powerdown_val);
    }
}




//-----------------------------------------------------------------------------
//
//-----------------------------------------------------------------------------
void si470x_reg_read (u8 firstreg, u8 lastreg) 
{
 	if (io_mode == IO3W) {
		io3w_read(firstreg, lastreg, si470x_shadow);
	} else {
	 	io2w_read(lastreg, si470x_shadow);
	}
}


//-----------------------------------------------------------------------------
//
//-----------------------------------------------------------------------------
void si470x_reg_write (u8 firstreg, u8 lastreg) 
{
 	if (io_mode == IO3W) {
		io3w_write(firstreg, lastreg, si470x_shadow);
	} else {
		io2w_write(lastreg, si470x_shadow);
	}
}