802.11a/b/g/n 20Mhz channel BW DDC configuration target solution for GC5016.

Hello

The GC5016 DDC and DUC can be programmed for 802.11 20Mhz bands.  Typically this is a multiple of 22.4Msps.  The GC5016 in a dec6, interp 6 can be used for DDC and DUC functions.  ChAB can be used as a DUC channel, ChCD can be used as a DDC channel. 

22.4Msps IQ * 6 = >134.4Mhz clock rate

The GC5016 does have a complex mixer at the input.  However there is no IQ correction for using a Quadrature demodulator architecture.  In most cases a real IF ADC is used with the GC5016. 

Example connections (could use TSW4100 schematic as a starting example)

ADC (2s complement) -> Cinput

DDC output D output for interleaved TDM (BQ<Bi,AQ,AI) output occurs for 4 of every 6 134.4Mhz clocks.  Using the parIQ mode C output, D output would be one output

every 6 clocks.

DUC input A for interleaved TDM (AI,AQ,BI,BQ) input occurs with Frame Strobe AFS trigger 4 of every 6 134.4Mhz clocks.  Using the parIQ mode A and B input, would be one input every 6 clocks.

The 16bit IO interface uses WEB, RDB and CEB for the GC5016.  Following the EMIF A guideline, you will need to decode these control strobes.

The DDC output, and DUC input do not directly connect to the DSP, you will need a FIFO interface to the EMIF bus, a small CPLD can do this. 

The configuration of the part, should follow the Using cmd5016 guide on the TI web site. 

The 6748 DSP to GC5016 could be done with CPLD Baseband IO to EMIFA FIFOs, or could be done using a different DSP bus structure.  This is not included in the gc5016

description.

Regards,

Radio Joe