si47xxamrx.c

this is Si47xx Example Code

	PoweredUp = 0;

    // Perform a hardware reset, power up the device, and then perform the
    // initial configuration.
    si47xx_reset();
    si47xxAMRX_powerup();
    si47xxAMRX_configure();
}

void si47xxAMSWLWRX_initialize(void)
{
    // Zero status registers.
	PoweredUp = 0;

    // Perform a hardware reset, power up the device, and then perform the
    // initial configuration.
    si47xx_reset();
    si47xxAMRX_powerup();
    si47xxAMSWLWRX_configure();
}

//-----------------------------------------------------------------------------
// Set the volume and mute/unmute status
//
// Inputs:
//      volume:    a 6-bit volume value
//
// Note: It is assumed that if the volume is being adjusted, the device should
// not be muted.
//-----------------------------------------------------------------------------
void si47xxAMRX_set_volume(u8 volume)
{
    // Turn off the mute
    si47xx_set_property(RX_HARD_MUTE, 0);

    // Set the volume to the passed value
    si47xx_set_property(RX_VOLUME, (u16)volume & RX_VOLUME_MASK);
}

//-----------------------------------------------------------------------------
// Mute/unmute audio
//
// Inputs:
//      mute:  0 = output enabled (mute disabled)
//             1 = output muted
//-----------------------------------------------------------------------------
void si47xxAMRX_mute(u8 mute)
{
    if(mute)
    	si47xx_set_property(RX_HARD_MUTE, 
                                RX_HARD_MUTE_RMUTE_MASK | RX_HARD_MUTE_LMUTE_MASK);
    else
    	si47xx_set_property(RX_HARD_MUTE, 0);
}

//-----------------------------------------------------------------------------
// Tunes to a station number using the current band and spacing settings.
//
// Inputs:
//      frequency:  frequency in 1kHz steps
//
// Returns:
//      The RSSI level found during the tune.
//-----------------------------------------------------------------------------
u8 si47xxAMRX_tune(u16 frequency)
{
	// Enable the bit used for the interrupt of STC.
	SeekTuneInProc = 1;

	// Call the tune command to start the tune.
 	WaitSTCInterrupt = 1;
    amTuneFreq(frequency);

    // wait for the interrupt before continuing
    // If you do not wish to use interrupts but wish to poll the part
    // then comment out this line.
    while (WaitSTCInterrupt); // Wait for interrupt to clear the bit

    // Wait for stc bit to be set
    while (!(getIntStatus() & STCINT));

	// Clear the STC bit and get the results of the tune.
    amTuneStatus(0, 1);

	// Disable the bit used for the interrupt of STC.
	SeekTuneInProc = 0;

    // Return the RSSI level
    return RSSI;
}

//-----------------------------------------------------------------------------
// Inputs:
//      seekup:  0 = seek down
//               1 = seek up
//      seekmode: 0 = wrap at band limits
//                1 = stop at band limits
// Outputs:
//      zero = seek found a station
//      nonzero = seek did not find a station
//-----------------------------------------------------------------------------
u8 si47xxAMRX_seek(u8 seekup, u8 seekmode)
{
	// Enable the bit used for the interrupt of STC.
	SeekTuneInProc = 1;

	// Call the tune command to start the seek.
 	WaitSTCInterrupt = 1;
    amSeekStart(seekup, !seekmode);

    // wait for the interrupt before continuing
    // If you do not wish to use interrupts but wish to poll the part
    // then comment out these two lines.
    while (WaitSTCInterrupt); // Wait for interrupt to clear the bit

    // Wait for stc bit to be set
    // If there is a display to update seek progress, then you could
    // call fmTuneStatus in this loop to get the current frequency.
    // When calling fmTuneStatus here make sure intack is zero.
    while (!(getIntStatus() & STCINT));

	// Clear the STC bit and get the results of the tune.
    amTuneStatus(0, 1);

	// Disable the bit used for the interrupt of STC.
	SeekTuneInProc = 0;

    // The tuner is now set to the newly found channel if one was available
    // as indicated by the seek-fail bit.
    return BLTF; //return seek fail indicator
}

//-----------------------------------------------------------------------------
// Returns the current tuned frequency of the part
//
// Returns:
//      frequency in 1kHz steps
//-----------------------------------------------------------------------------
u16 si47xxAMRX_get_frequency()
{
	// Get the tune status which contains the current frequency
    amTuneStatus(0, 0);

    // Return the frequency
    return Freq;
}

//-----------------------------------------------------------------------------
// Returns the current tuned frequency of the part
//
// Returns:
//      frequency in 10kHz steps
//-----------------------------------------------------------------------------
u8 si47xxAMRX_get_rssi()
{
	// Get the tune status which contains the current frequency
	amTuneStatus(0,0);  // This should be changed to Rsq status when working.

    // Return the RSSI level
    return RSSI;
}

//-----------------------------------------------------------------------------
// Helper function that sends the AM_TUNE_FREQ command to the part
//
// Inputs:
// 	frequency in 1kHz steps
//-----------------------------------------------------------------------------
static void amTuneFreq(u16 frequency)
{
    // Put the ID for the command in the first byte.
    cmd[0] = AM_TUNE_FREQ;

	// Initialize the reserved section to 0
    cmd[1] = 0;

	// Put the frequency in the second and third bytes.
    cmd[2] = (u8)(frequency >> 8);
	cmd[3] = (u8)(frequency & 0x00FF);

	// Set the antenna calibration value.
    cmd[4] = (u8)0;  // Auto
	cmd[5] = (u8)0;

    // Invoke the command
	si47xx_command(6, cmd, 1, rsp);
}

//-----------------------------------------------------------------------------
// Helper function that sends the AM_SEEK_START command to the part
//
// Inputs:
// 	seekUp: If non-zero seek will increment otherwise decrement
//  wrap:   If non-zero seek will wrap around band limits when hitting the end
//          of the band limit.
//-----------------------------------------------------------------------------
static void amSeekStart(u8 seekUp, u8 wrap)
{
    // Put the ID for the command in the first byte.
    cmd[0] = AM_SEEK_START;

	// Put the flags if the bit was set for the input parameters.
	cmd[1] = 0;
    if(seekUp) cmd[1] |= AM_SEEK_START_IN_SEEKUP;
	if(wrap)   cmd[1] |= AM_SEEK_START_IN_WRAP;

    // Invoke the command
	si47xx_command(2, cmd, 1, rsp);
}

//-----------------------------------------------------------------------------
// Helper function that sends the AM_TUNE_STATUS command to the part
//
// Inputs:
// 	cancel: If non-zero the current seek will be cancelled.
//  intack: If non-zero the interrupt for STCINT will be cleared.
//
// Outputs:  // These are global variables and are set by this method
//  STC:    The seek/tune is complete
//  BLTF:   The seek reached the band limit or original start frequency
//  AFCRL:  The AFC is railed if this is non-zero
//  Valid:  The station is valid if this is non-zero
//  Freq:   The current frequency
//  RSSI:   The RSSI level read at tune.
//  ASNR:   The audio SNR level read at tune.
//  AntCap: The current level of the tuning capacitor.
//-----------------------------------------------------------------------------
static void amTuneStatus(u8 cancel, u8 intack)
{
    // Put the ID for the command in the first byte.
    cmd[0] = AM_TUNE_STATUS;

	// Put the flags if the bit was set for the input parameters.
	cmd[1] = 0;
    if(cancel) cmd[1] |= AM_TUNE_STATUS_IN_CANCEL;
	if(intack) cmd[1] |= AM_TUNE_STATUS_IN_INTACK;

    // Invoke the command
	si47xx_command(2, cmd, 8, rsp);

    // Parse the results
    STC    = !!(rsp[0] & STCINT);
    BLTF   = !!(rsp[1] & AM_TUNE_STATUS_OUT_BTLF);
    AFCRL  = !!(rsp[1] & AM_TUNE_STATUS_OUT_AFCRL);
    Valid  = !!(rsp[1] & AM_TUNE_STATUS_OUT_VALID);
    Freq   = ((u16)rsp[2] << 8) | (u16)rsp[3];
    RSSI   = rsp[4];
    ASNR   = rsp[5];
    AntCap = ((u16)rsp[6] << 8) | (u16)rsp[7];   
}