Topic: FMC30RF BOARD AND REFERENCE DESIGN QUESTIONS  (Read 4460 times)

kcfarleyswmacb October 10, 2013, 06:00 PM

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1) Please elaborate what 14 bit 16 bit left aligned complex samples mean.
 
In Reference Design Details at the end there is a statement:
 
-   The data format is 14-bit, 16-bit left aligned complex samples with I and Q samples interleaved.

2) I want to inject a signal into RF IN of FMC30RF from a agilent analog generator.
     a) A sine wave offset from tx tune frequency.
     b) What is acceptable input range of RF IN for dBM and voltages?
     c) What is a good nominal value?
 

arnaudNL October 11, 2013, 04:24 AM (#1)

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Dear Sir,


1)


There are 14 bits of data which are left aligned on 16 bits word.


The data is placed on bits 13 down to 2, bits 1 and 0 being nothing. I Q interleaved means that the sequence in the buffer looks like the following


I0Q0I1Q1I2Q2I3Q3...


2)
I will get one of my colleague to provide you with this information, it is not part of the user manual indeed.



kcfarleyswmacb October 11, 2013, 09:48 AM (#2)

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Just to make sure I really understand 14 bit 16 bit left aligned:
   Take 14 bit vector and concatenate two zeroes into bit 0 and bit 1 to make a 16 bit vector
 
VHDL
 
        (14 bit vector) & '0' & '0'

arnaudNL October 14, 2013, 04:15 AM (#3)

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Dear Sir,


From the VHDL source code delivered with the BSP:


 rx_data_i <= adc_i & "0000";


 dac_a <= tx_data_i(15 downto 4);


Best Regards,
Arnaud

hzh0608 February 26, 2014, 11:18 PM (#4)

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Dear Sir,


1)


There are 14 bits of data which are left aligned on 16 bits word.


The data is placed on bits 13 down to 2, bits 1 and 0 being nothing. I Q interleaved means that the sequence in the buffer looks like the following


I0Q0I1Q1I2Q2I3Q3...


2)
I will get one of my colleague to provide you with this information, it is not part of the user manual indeed.




Dear Sir,
     I am also eager to know [size=78%] a) What is acceptable input range of RF IN for dBM and voltages?[/size]     b) What is a good nominal value?   Can you invite your colleague to answer this.  I would be very grateful.


     Thanks.
     Marchzh

peter February 27, 2014, 04:22 PM (#5)

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Hello Marchzh,


Please find attached the test results for input power (BB gain and 3dB att refers to TRF3711 settings). Best Regards,


Peter

peter March 13, 2014, 12:49 PM (#6)

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This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.