Mixer - david-macmahon/wiki_convert_test GitHub Wiki
Block: Mixer (mixer)
Block Author: Aaron Parsons
Document Author: Aaron Parsons, Ben Blackman
Summary
Digitally mixes an input signal (which can be several samples in parallel) with an LO of the indicated frequency (which is some fraction of the native FPGA clock rate).
Mask Parameters
| Parameter | Variable | Description |
|---|---|---|
| Frequency Divisions | freq_div | The (power of 2) denominator of the mixing frequency. |
| Mixing Frequency | freq | The numerator of the mixing frequency. |
| Number of Parallel Streams | nstreams | The number of samples that arrive in parallel. |
| Bit Width | n_bits | The bitwidth of LO samples. |
| BRAM Latency | bram_latency | The latency of sin/cos lookup table. |
| MULT Latency | mult_latency | The latency of mixing multipliers. |
Ports
| Port | Dir | Data Type | Description |
|---|---|---|---|
| sync | IN | boolean | Takes in an impulse the cycle before the dins are valid. |
| dinX | IN | Fix_8_7 | Input X to be mixed and output on realX and imagX. |
| sync_out | OUT | boolean | This signal will be high the cycle before the data coming out is valid. |
| realX | OUT | Fix_(n_bits)_(n_bits-1) | Real output of mixed dinX. |
| imagX | OUT | Fix_(n_bits)_(n_bits-1) | Imaginary output of mixed dinX. |
Description
Usage
Mixer mixes the incoming data and produces both real and imaginary
outputs.
(M) = Frequency Divisions (F) = Mixing Frequency M and F must both be integers, and M must be a power of 2. The ratio F/M should equal the ratio f/r where r is the data rate of the sampled signal. For example, an F/M of 3/16 would downmix an 800Msps signal with an LO of 150MHz.