117
A3.8.4
Algorithm D
Algorithm steps:
1.
Apply a single tone at frequency equal to “CalFreq”
2.
Compare the amplitude at the input ADC to “LowFreqAmp”. If greater, then the pre-
emphasis zero is faster than the real pole. And Vise-Versa. Decrease or increase
respectively the zero frequency by one step.
3.
If the last step was in the opposite direction of the current step, then you have reached
the optimal value of the pre-emphasis parameters. (the last step you increased by one
step and this step you decreased, or, the last step you decreased and this step you
increased). If not, then go back to step 2.
4.
Store pre-emphasis zero setting.
C code for algorithm D:
unsigned char Algorithm_D_TBB (unsigned char Band_id)
{
unsigned short ADCOUT;
unsigned char inc, Zero_Freq = 127;
Set_NCO_Freq (TBB_CalFreq[Band_id]); // 1 Apply a single tone at frequency equal to “CalFreq”
ADCOUT = Get_SPI_Reg_bits(0x040B, 15, 0); //RSSI value
if(ADCOUT > LowFreqAmp) inc = 0; //If greater, then the pre-emphasis zero is faster than the real pole
else inc = 1;
while (1)
{
ADCOUT = Get_SPI_Reg_bits(0x040B, 15, 0); //RSSI value // Measure the output level at the ADC input
if (inc)
{
if(ADCOUT >= 52428) break;
}
else
{
if(ADCOUT <= 52428) break;
}
if( (Zero_Freq == 0) || (Zero_Freq == 255)) //gain limit reached
{
return 0;
break;
}
if(inc) Ze+;
else Zero_Freq--;
}
}
A3.8.5
Algorithm E
1.
If(“CalFreq”)
<=11MHz,
then
CONTROL=RCAL_LPFLAD_TBB,
else,
CONTROL=RCAL_LPFH_TBB
2.
Set the CONTROL to zero. This should bring the output cutt-off frequency to
minimum.
3.
Apply Algorithm B.
4.
Apply a single tone frequency at “CalFreq”.
5.
Measure the value of the amplitude at the ADC input. This value should be lower than
“LowFreqAmp”.
6.
Increase the CONTROL value by one.
7.
Measure the value of the amplitude at the ADC input. If it is lower than
“LowFreqAmp”, then jump back to line#3. Otherwise continue to step 8.
Summary of Contents for LMS7002M Series
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