AnsweredAssumed Answered

Clarification on interfacing ADF7020

Question asked by divakar on Aug 9, 2011
Latest reply on Aug 11, 2011 by enash



I am using ADF7020 (daughter board with 11.0592MHz XTAL) to design a RF UHF reader which reads the data in the RFID tag (passive), as the tag comes within the range. I use dsPIC33fj256gp710 for interfacing with ADF7020. I will have to show the Tag data onto a computer hyperterminal (UART), as the tag comes within the range.


I understand the ADF7020 register values has to be communicated from dsPIC to ADF7020 serially, using the reference of the waveform shown in the ADF7020 website (pg 8). After latching all these register values into ADF7020 through SLE pin, the readback code is read from the SREAD pin of ADF7020 by setting SLE high and by initiating the clock from dsPIC (as dsPIC is master). Once this is done i understand that the ADF transceiver is initiated and is ready to read the data from the tag. If what I understood above is wrong, please correct me.


Besides, what I do not understand is, how to read the tag data from the ADF7020 IC (if a tag comes within the range), I also have seen the waveform shown for RxDATA and RXCLK at ADF7020 datasheet (pg 9). I presume, these are the DATA_CLK and DATA_I/O pins connected to appropriate I/O pins of dsPIC. But, what I do not understand is, should I code the dsPIC so that the RxCLK pin continue to oscillate forever (after ADF IC is initiated), and whenever the tag comes within the range, the ADF IC automatically emits the Tag data serially as per the clock pulses ?  Or, will the ADF7020 Ic will initiate the clock pulses also if any tag comes within the range ? Or, how exactly the dsPIC reads data from ADF7020 IC ?


Can someone help ?


Divakar Raj. R