detailed subsystems

docs/ps_subsystem.md

@@ -1,33 +1,85 @@
-# 🧠 PS Subsystem
+# 🧠 PS Subsystem (Control + Processing)
+
+[🏠 Project Home](../README.md)
+
+---
 
 ## Overview
 
-Handles control and processing.
+The PS subsystem is responsible for:
+
+- Configuring PL subsystems
+- Receiving data via DMA
+- Performing frame-based processing
 
 ---
 
-## Control
+## Responsibilities
 
-- Writes parameters
-- Triggers Tx (TxPulseStart)
+### Control
+
+- Writes parameters to PL registers:
+  - Tx generator configuration
+- Generates TxPulseStart trigger
 
 ---
 
-## Processing
+### DMA Handling
 
-DMA → unpack → complex → RMS/peak
+- AXI4-Stream → DMA (S2MM)
+- Data stored in PS DDR
+
+Configuration:
+- Frame size: 512
+- Buffers: 16
 
 ---
 
-## Execution
+### Processing Pipeline
 
-- Event-driven
-- Frame drops possible
+DMA → uint64[512]  
+→ unpack real/imag  
+→ convert to complex  
+→ RMS + peak detection  
+
+---
+
+## Execution Model
+
+- Event-driven (DMA trigger)
+- No buffering queue
+- Frames may be dropped
+
+---
+
+## Performance Notes
+
+- Bottleneck: unpacking + conversion
+- Cannot sustain full-rate input
+
+---
+
+## Interaction with PL
+
+### Tx Control
+- Low-rate trigger (~Hz)
+- Starts burst generation
+
+### Rx Data
+- Continuous high-rate stream
+
+---
+
+## Future Work
+
+- Replace processing with FrFT
+- NEON optimization
+- Throughput improvements
 
 ---
 
 ## 🔗 Related Components
 
-- [Project Overview (README)](../README.md)
+- [🏠 Project Home](../README.md)
 - [PL Tx Subsystem](pl_tx_subsystem.md)
 - [PL Rx Subsystem](pl_rx_subsystem.md)