diff --git a/docs/pl_rx_subsystem.md b/docs/pl_rx_subsystem.md index 66d09bc..766091c 100644 --- a/docs/pl_rx_subsystem.md +++ b/docs/pl_rx_subsystem.md @@ -8,12 +8,16 @@ The Rx subsystem implements a **polyphase filter bank (PFB) channelizer** followed by FFT processing. -It converts wideband ADC input into frequency-domain channels. +It converts wideband ADC input into frequency-domain channels and streams the result to the PS. + +A **bypass path** is also available for raw data inspection and debugging. --- ## Architecture +### Channelizer Path (default) + ADC ↓ PFB Channelizer (Decimation + Filtering) @@ -30,7 +34,55 @@ DMA --- -## Processing Chain +### Bypass Path (Debug / Raw Data) + +ADC + ↓ +Bypass Path + ↓ +FIFO / Serializer + ↓ +AXI4-Stream + ↓ +DMA + +--- + +## Bypass Functionality + +The bypass allows direct observation of the input signal without channelization. + +### Purpose + +- Debugging and validation +- Access to raw ADC-domain data +- Comparison with channelized output +- Verification of downstream processing + +--- + +### Behavior + +- Input data is routed directly to output +- No filtering or FFT applied +- Maintains same output interface (AXI4-Stream) + +--- + +### Selection Mechanism + +A selector signal chooses between: + +- Channelizer output (normal operation) +- Bypass output (raw data) + +Implementation typically uses: +- Parallel paths +- Output switching logic + +--- + +## Processing Chain (Channelizer Mode) ### ADC Input - Sampling rate: 4096 MSPS @@ -71,7 +123,7 @@ DMA - Fully streaming pipeline - High throughput - Deterministic latency -- DMA-ready output +- Supports dual-mode operation (channelizer / bypass) ---