obsidian-vault-/BBU/Untitled.md

# STDRPI880001 Module Architecture

  

## Overview

The STDRPI880001 is a base board serving as the foundation for a test stand that manages and controls various daughter boards including UCBX86880001, UBBX86880001, FANCTL880001, IOBALR880001, IOBSYN880001, and BPLUNI880001.

  

## Physical Architecture

  

### Power Supply System

- **Primary Power**: 12V external power supply with reverse polarity protection and input filtering

- **Secondary Power Supplies**:

  - 5V (6A) for Raspberry Pi and USB peripherals

  - 3.3V (current determined during development)

  - 1V (FPGA core voltage)

  - 1.1V (switch voltage)

  

### Board Integration

- **Raspberry Pi 5**: Direct connection via flat cable to IDC connector (2x20 2.54mm pitch)

- **FPGA**: GW2A-LV55PG484C8/I7 with external configuration PROM and connector for programming

- **Ethernet Switch**: RTL8367RBI-VH-CG with 5 ports (4 to UCB, 1 to UBB) and external PHY connection

  

## Core Components

  

### Control and Communication

- **JTAG Interface**: Adafruit FTDI FT232H programmer adapter for board programming and debugging

- **I2C Bus**: Raspberry Pi I2C connections (SDA, SCL) to FPGA pins AB3 and AB4

- **UART Interface**: Raspberry Pi UART connections (Tx, Rx) to FPGA pins R1 and R2

- **SPI Interface**: For flash memory and other peripheral communication

  

### Power Management

- **48V Distribution**: Up to 7A power distribution to UxB boards with galvanic isolation

- **12V Distribution**: Up to 21A power distribution to FANCTL, IOBALR, IOBSYN boards with galvanic isolation

- **Fan Control**: Three separate fan channels with current/voltage monitoring and PWM control

- **Power Monitoring**: Current and voltage measurement capabilities for all power rails

  

### Signal Routing

- **Status & Control Signals**: Comprehensive signal routing to all test boards

- **Synchronization Signals**: LVDS signals for precise timing synchronization

- **Ethernet Interfaces**: MDI interfaces for network connectivity to test boards

  

## Connector Architecture

  

### POGO Connectors

- **POGO20 Connectors**: For FANCTL, IOBALR, and IOBSYN boards

- **POGO40 Connectors**: For UxB boards (40-pin connectors)

  

### Specific Board Connectors

- **IOBALR Connectors**: Dedicated connectors for IOBALR boards

- **IOBSYN Connectors**: Dedicated connectors for IOBSYN boards

- **FANCTL Connectors**: Dedicated connectors for FANCTL boards

- **UBB Connectors**: Dedicated connectors for UBB boards

- **UCB Connectors**: Dedicated connectors for UCB boards

  

## Software and Control Interface

  

### Raspberry Pi Interface

- **GPIO Mapping**: Detailed pin mapping for Raspberry Pi GPIO connections

- **I2C Interface**: Standard I2C bus for communication with peripheral devices

- **UART Interface**: Serial communication for debugging and monitoring

- **SPI Interface**: For flash memory and other peripherals

  

### FPGA Control

- **Signal Processing**: FPGA handles signal routing and control for all connected boards

- **Protocol Handling**: Implementation of I2C, UART, and other protocols

- **Timing Control**: Generation and handling of synchronization signals

  

## Revision Information

  

### Available Revisions

- **Revision A**: Original design with specific component placements

- **Revision B**: Updated design with changes to shunt resistors and other improvements

  

### Schematic and Layout

- **Schematic Files**: Available in repository for both revisions

- **PCBA Orders**: Specific orders for each revision

- **Firmware**: Firmware updates for different revisions

  

## Test Board Compatibility

  

### Supported Daughter Boards

1. **UCBX86880001** (UCB)

2. **UBBX86880001** (UBB)

3. **FANCTL880001** (FANCTL)

4. **IOBALR880001** (IOBALR)

5. **IOBSYN880001** (IOBSYN)

6. **BPLUNI880001** (BPLUNI)

  

## Key Features

  

### Power Distribution

- Dedicated power distribution for different test board types

- Current and voltage monitoring capabilities

- Galvanic isolation for safety and measurement accuracy

  

### Signal Management

- Comprehensive signal routing to all test boards

- JTAG interface for programming and debugging

- I2C, UART, and GPIO interfaces for communication

  

### Monitoring and Control

- Temperature monitoring (internal and external)

- Sensor interfaces for inductive metal sensors

- Fan control with PWM and monitoring

- Power supply monitoring for external sources

  

## Technical Specifications

  

### Electrical Characteristics

- Input Voltage: 12V DC

- Power Consumption: Varies by connected boards

- Signal Levels: 3.3V CMOS logic levels

- Timing Accuracy: 25ppm crystal oscillator

  

### Mechanical Specifications

- Connector Types: IDC, POGO, and standard board connectors

- Mounting: Standard PCB mounting

- Dimensions: As defined in schematic documentation

  

## Repository References

- FPGA Implementation: ssh://git@b.yadro.com:7999/hwstait/tstuxb880001.git

- Ethernet Switch: ssh://git@b.yadro.com:7999/hwstait/tstuxb880001.git and ssh://git@b.yadro.com:7999/hwstait/ucbx86880001.git

- Power Supply Schematics: ssh://git@b.yadro.com:7999/hwstait/ucbx86880001.git

- Fan Control: ssh://git@b.yadro.com:7999/hwstait/fanctl880001.git