# 🧠 PS Subsystem (Control + Capture + Processing)

[🏠 Project Home](../README.md)

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## Overview

The PS subsystem is responsible for:

- System initialization
- Configuring PL subsystems
- Triggering captures
- Receiving data via DMA
- Preparing data for processing and visualization

The current implementation acts as a **placeholder for post-processing**, focusing on reliable data acquisition and host interaction.

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## Responsibilities

### Control & Initialization

- Configure PL parameters:
  - Tx waveform configuration
  - Capture parameters (nFrames, etc.)
- Initialize DMA and memory buffers
- Manage system startup

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### Trigger & Capture

- Generates capture trigger (software-controlled)
- Controls DPW acquisition timing
- Each trigger initiates one DPW capture

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### DMA Handling

- AXI4-Stream → DMA (S2MM)
- Receives **128-bit stream** (4 samples per clock)
- Stores data in PS DDR memory

Configuration:
- Frame size: 512 samples
- nFrames: configurable (validated up to 1024)

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## Data Format

### Raw DMA Data

- Packed complex samples
- 16-bit real + 16-bit imag per sample
- 4 samples per 128-bit word

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### Processing Representation

Data is unpacked and reshaped into:

```
[FrameSize x nFrames x nTriggers]
```

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## Processing Pipeline (Current)

DMA  
→ Unpack samples (I/Q separation)  
→ Convert to complex representation  
→ Reshape into 3D structure  
→ Visualization / basic analysis  

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## Validation Support

Uses counter-based validation:

- Real part → sample counter
- Imag part → frame index

Enables verification of:

- Data continuity
- Frame alignment
- Correct ordering from DMA

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## Execution Model

- Triggered (event-based)
- Burst capture (DPW)
- Not continuous real-time streaming

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## Performance Notes

- Designed for correctness and validation (not optimized)
- Bottleneck: unpacking + data movement
- Full-rate continuous processing not supported

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## Role in System

The PS currently serves as:

- Control interface
- Data acquisition manager
- Pre-processing stage

Future implementations will replace the current processing with advanced algorithms (e.g., FrFT).

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## Future Work

- FrFT-based processing
- Timestamp integration
- UDP streaming
- Optimization (NEON / vectorization)
- Metadata extraction (move complexity to PL)

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## 🔗 Related Components

- [🏠 Project Home](../README.md)
- [PL Tx Subsystem](pl_tx_subsystem.md)
- [PL Rx Subsystem](pl_rx_subsystem.md)