# FPGA Programming and Hardware Description - Processes Backlog

## Overview

This document contains the Phase 2 processes backlog for the FPGA Programming and Hardware Description specialization. These processes cover the complete FPGA development lifecycle from RTL design through synthesis, verification, and deployment.

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## Category: RTL Design and Development

### 1. RTL Module Architecture Design
**Priority:** High
**Complexity:** Medium
**Description:** Design and document the architecture for RTL modules including interface definitions, internal data paths, control logic, and timing requirements. Establish module hierarchy and define signal naming conventions.

**Key Activities:**
- Define module interfaces and port specifications
- Design internal datapath architecture
- Specify control logic and state machine structure
- Document timing diagrams and waveforms
- Create block diagrams and architecture documentation

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### 2. VHDL Module Development
**Priority:** High
**Complexity:** Medium
**Description:** Develop synthesizable VHDL modules following IEEE 1076 standards and industry best practices. Implement entities, architectures, and packages with proper use of numeric_std library and synchronous design methodology.

**Key Activities:**
- Write entity declarations with generics and ports
- Implement RTL architectures with processes
- Create reusable packages and components
- Apply VHDL synthesis coding guidelines
- Document module functionality and constraints

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### 3. Verilog/SystemVerilog Design Implementation
**Priority:** High
**Complexity:** Medium
**Description:** Implement digital designs using Verilog or SystemVerilog following IEEE 1800 standards. Create parameterized modules with proper use of always_ff, always_comb, and interface constructs.

**Key Activities:**
- Develop parameterized module definitions
- Implement sequential and combinational logic
- Use SystemVerilog interfaces for complex connections
- Apply SystemVerilog assertions (SVA) for design intent
- Follow vendor-specific coding guidelines for synthesis

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### 4. Finite State Machine (FSM) Design
**Priority:** High
**Complexity:** Medium
**Description:** Design and implement finite state machines using one-hot, binary, or Gray encoding. Create clear state transition logic with proper reset behavior and output registration.

**Key Activities:**
- Define state encoding strategy
- Implement state register and next-state logic
- Design output logic (Moore/Mealy)
- Handle illegal state recovery
- Document state diagrams and transition tables

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### 5. Pipeline Architecture Implementation
**Priority:** High
**Complexity:** High
**Description:** Design and implement pipelined architectures to achieve high throughput. Balance pipeline stages for timing closure while managing hazards and data dependencies.

**Key Activities:**
- Analyze critical paths for pipeline insertion points
- Design pipeline registers and control signals
- Implement hazard detection and forwarding logic
- Balance latency vs throughput tradeoffs
- Verify pipeline behavior under backpressure

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## Category: Verification and Testing

### 6. Testbench Development
**Priority:** High
**Complexity:** Medium
**Description:** Create comprehensive testbenches for RTL verification including stimulus generation, response checking, and coverage collection. Use SystemVerilog verification features or VHDL testbench patterns.

**Key Activities:**
- Design testbench architecture and components
- Implement stimulus generators and drivers
- Create scoreboarding and checking logic
- Add functional coverage collection
- Develop self-checking test mechanisms

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### 7. Functional Simulation and Debug
**Priority:** High
**Complexity:** Medium
**Description:** Execute functional simulations to verify RTL behavior against specifications. Debug failing tests using waveform analysis and signal tracing.

**Key Activities:**
- Set up simulation environment and scripts
- Run directed and random test scenarios
- Analyze waveforms for functional correctness
- Debug failing tests with root cause analysis
- Document simulation results and coverage

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### 8. SystemVerilog Assertion (SVA) Development
**Priority:** Medium
**Complexity:** Medium
**Description:** Implement concurrent and immediate assertions to verify design properties. Create assertion libraries for protocol checking and design intent specification.

**Key Activities:**
- Write property specifications for design requirements
- Implement concurrent assertions for protocol checking
- Add coverage properties for functional verification
- Create reusable assertion libraries
- Integrate assertions with formal verification flows

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### 9. Constrained Random Verification (CRV)
**Priority:** Medium
**Complexity:** High
**Description:** Develop constrained random testbenches using SystemVerilog randomization features. Create constraint classes and coverage models for thorough verification.

**Key Activities:**
- Define transaction classes with constraints
- Implement sequence and virtual sequence layers
- Create coverage groups and coverpoints
- Develop coverage-driven verification strategy
- Analyze and close coverage holes

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### 10. UVM Testbench Architecture
**Priority:** Medium
**Complexity:** High
**Description:** Design and implement Universal Verification Methodology (UVM) testbenches following IEEE 1800.2 standard. Create reusable verification components and test infrastructure.

**Key Activities:**
- Architect UVM testbench environment
- Implement agents, drivers, and monitors
- Design scoreboards and predictors
- Create test sequences and virtual sequences
- Configure factory and reporting mechanisms

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## Category: Synthesis and Implementation

### 11. Synthesis Optimization
**Priority:** High
**Complexity:** Medium
**Description:** Optimize RTL for synthesis to meet area, timing, and power goals. Apply synthesis directives and attributes to guide tool optimization.

**Key Activities:**
- Analyze synthesis reports and resource utilization
- Apply synthesis attributes and directives
- Optimize logic structure for target technology
- Manage DSP and memory inference
- Iterate on RTL for synthesis quality improvement

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### 12. Timing Constraint Development
**Priority:** High
**Complexity:** High
**Description:** Develop comprehensive timing constraints (SDC/XDC) including clock definitions, input/output delays, false paths, and multicycle paths. Ensure constraint completeness and correctness.

**Key Activities:**
- Define clock constraints and relationships
- Specify input and output delay constraints
- Identify and constrain false paths
- Define multicycle paths correctly
- Validate constraint coverage and completeness

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### 13. Timing Closure Strategies
**Priority:** High
**Complexity:** High
**Description:** Achieve timing closure through systematic analysis and optimization techniques. Apply RTL modifications, constraint refinements, and tool directives to meet timing requirements.

**Key Activities:**
- Analyze timing reports and critical paths
- Apply pipelining and logic restructuring
- Use physical constraints for critical logic
- Iterate between synthesis and implementation
- Document timing closure process and results

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### 14. Place and Route Optimization
**Priority:** High
**Complexity:** High
**Description:** Optimize placement and routing to achieve timing closure and minimize resource utilization. Use floorplanning, placement constraints, and routing directives.

**Key Activities:**
- Create floorplans for large designs
- Apply placement constraints (PBLOCK, LOC)
- Optimize routing congestion
- Use physical optimization strategies
- Perform incremental implementation for timing preservation

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## Category: Clock and Reset Design

### 15. Clock Domain Crossing (CDC) Design
**Priority:** High
**Complexity:** High
**Description:** Design and verify safe clock domain crossing circuits. Implement synchronizers, handshake protocols, and asynchronous FIFOs with proper CDC techniques.

**Key Activities:**
- Identify all clock domain crossings
- Implement appropriate synchronization circuits
- Design asynchronous FIFOs with Gray code pointers
- Apply CDC constraints and false paths
- Verify CDC correctness with structural checks

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### 16. Reset Strategy Design
**Priority:** High
**Complexity:** Medium
**Description:** Design robust reset distribution and synchronization for single and multi-clock domain designs. Implement reset sequencing and de-assertion synchronization.

**Key Activities:**
- Define reset architecture and hierarchy
- Implement reset synchronizers for async resets
- Design reset sequencing logic
- Handle reset domain crossings
- Document reset requirements and behavior

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### 17. Clock Network Design and Constraints
**Priority:** Medium
**Complexity:** Medium
**Description:** Design clock distribution networks using global and regional clock resources. Define clock relationships and constraints for derived clocks and PLLs/MMCMs.

**Key Activities:**
- Define clock architecture and sources
- Configure PLL/MMCM for clock generation
- Specify clock group relationships
- Constrain generated and derived clocks
- Verify clock network implementation

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## Category: IP Integration and Interfaces

### 18. IP Core Integration
**Priority:** High
**Complexity:** Medium
**Description:** Integrate vendor IP cores and custom IP blocks into designs. Configure IP parameters, connect interfaces, and verify integration correctness.

**Key Activities:**
- Select and configure IP cores
- Connect IP interfaces to design
- Handle clock and reset for IP blocks
- Verify IP integration and functionality
- Document IP configuration and usage

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### 19. AXI Interface Design and Implementation
**Priority:** High
**Complexity:** High
**Description:** Design and implement AMBA AXI interfaces including AXI4, AXI4-Lite, and AXI4-Stream. Create masters, slaves, and interconnect logic following ARM AMBA specifications.

**Key Activities:**
- Implement AXI protocol state machines
- Design address decoding and routing
- Handle burst transactions correctly
- Implement flow control and buffering
- Verify protocol compliance

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### 20. Memory Interface Design
**Priority:** High
**Complexity:** Medium
**Description:** Design interfaces to on-chip Block RAM, distributed RAM, and external memory controllers. Implement memory access patterns optimized for bandwidth and latency.

**Key Activities:**
- Infer Block RAM and distributed memory correctly
- Design memory access controllers
- Implement read-first/write-first behavior
- Optimize memory bandwidth utilization
- Handle memory initialization and ECC

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## Category: Hardware Acceleration and HLS

### 21. High-Level Synthesis (HLS) Development
**Priority:** Medium
**Complexity:** High
**Description:** Develop hardware accelerators using C/C++ with High-Level Synthesis tools. Apply pragmas and directives to achieve desired performance and resource utilization.

**Key Activities:**
- Write synthesizable C/C++ code for HLS
- Apply interface synthesis directives
- Optimize loops and arrays for parallelism
- Analyze HLS reports and iterate on design
- Integrate HLS-generated IP into system

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### 22. Hardware-Software Co-Design
**Priority:** Medium
**Complexity:** High
**Description:** Design systems combining FPGA hardware with embedded processors (Zynq, MicroBlaze). Partition functionality between hardware and software for optimal performance.

**Key Activities:**
- Define hardware/software partitioning
- Design hardware accelerator interfaces
- Implement DMA and interrupt handling
- Optimize data movement between domains
- Verify co-design functionality

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## Category: Debug and Power Optimization

### 23. FPGA On-Chip Debugging
**Priority:** High
**Complexity:** Medium
**Description:** Implement and use on-chip debugging tools (ILA, VIO, ChipScope, SignalTap) for hardware debugging. Capture signals and analyze behavior in running hardware.

**Key Activities:**
- Insert Integrated Logic Analyzer (ILA) probes
- Configure trigger conditions
- Capture and analyze hardware signals
- Debug timing and functional issues
- Remove debug logic for production builds

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### 24. Power Analysis and Optimization
**Priority:** Medium
**Complexity:** Medium
**Description:** Analyze FPGA power consumption and apply optimization techniques. Use clock gating, power domains, and design techniques to reduce dynamic and static power.

**Key Activities:**
- Run power estimation tools
- Identify high-power consumption areas
- Apply clock enable strategies
- Optimize switching activity
- Validate power requirements are met

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### 25. Design for Testability (DFT)
**Priority:** Medium
**Complexity:** Medium
**Description:** Implement design-for-testability features including JTAG access, built-in self-test (BIST), and scan insertion for production testing of FPGA-based systems.

**Key Activities:**
- Design JTAG debug access
- Implement memory BIST
- Add error injection capabilities
- Create production test infrastructure
- Document test procedures and coverage

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## Summary

| Category | Process Count |
|----------|---------------|
| RTL Design and Development | 5 |
| Verification and Testing | 5 |
| Synthesis and Implementation | 4 |
| Clock and Reset Design | 3 |
| IP Integration and Interfaces | 3 |
| Hardware Acceleration and HLS | 2 |
| Debug and Power Optimization | 3 |
| **Total** | **25** |

## Implementation Notes

- Processes should be implemented as JavaScript modules following the existing specialization patterns
- Each process should include detailed phase definitions, quality gates, and tool integrations
- Reference the README.md for FPGA-specific terminology and concepts
- Reference the references.md for standards, vendor documentation, and best practices
- Prioritize high-priority processes for initial implementation
