ESH10000025 - GPIO Module

Overview

The ESH10000025 is a general-purpose I/O module providing 96 bidirectional digital channels organized into 6 banks with configurable voltage levels per bank.

Description

The GPIO Module provides 96 digital I/O channels across 6 independent banks (16 channels each), with per-bank voltage level control. This module is ideal for flexible digital interfacing, custom signal routing, and DUT control applications.

Key Features:

• 96 Digital I/O Channels: Organized into 6 banks of 16 channels

  • Bidirectional capability (IN/OUT configurable per channel)
  • Configurable pull-up/pull-down resistors
  • Push-pull or open-drain output modes
  • Bank-level register access for parallel operations

• 6 Voltage Output Controls (VIO_BANK): Independent voltage supply per bank

  • Range: 1.2V to 5.0V
  • 12-bit DAC resolution
  • Allows interfacing with different logic families simultaneously

• Bank Register Interface: Direct 8-bit register read/write per bank (A/B ports)

  • Enables fast parallel I/O operations
  • Hex or decimal value support
  • Automatic GPIO update on register write

Hardware Details

GPIO Expanders:

• Chip: NXP PI4IOE5V6416 (6 chips)
• Channels per chip: 16 (2 ports × 8 pins)
• Total channels: 96
• I²C Addresses:
  • U6: 0x20 (I2C0) - GPIO00-15
  • U7: 0x21 (I2C0) - GPIO16-31
  • U8: 0x20 (I2C1) - GPIO32-47
  • U9: 0x21 (I2C1) - GPIO48-63
  • U10: 0x20 (I2C2) - GPIO64-79
  • U11: 0x21 (I2C2) - GPIO80-95
• Communication: I²C bus

Voltage DAC:

• Chip: Microchip MCP47FEB18 (MCP47FXBX family)
• Channels: 6 outputs (2 DACs × 3 channels, interleaved addressing)
• Resolution: 12-bit
• I²C Address: 0x60
• Voltage Range: 1.2V - 5.0V (double DAC range mode enabled)
• Default Value: 1.8V per bank

I²C Multiplexer:

• Chip: TI PCA9540 or similar
• Address: 0x70
• Purpose: Routes I²C bus to internal I2C0, I2C1, I2C2 segments

Channel Naming Convention

All channels follow the naming pattern: {ModuleIndex}.ESH10000025.{ChannelName}

Example: Module at position 0, GPIO channel 42 would be: 0.ESH10000025.GPIO42

User-Accessible Channels

Total User Channels: 108 (96 GPIO + 6 VIO + 12 Register Banks)

Channel Configuration

Digital Channel Configuration

Each GPIO channel supports:

• Direction: IN or OUT (bidirectional capability)
• PullType: None, PullUp, or PullDown
• PushType: PushPull or OpenDrain
• DefaultValue: Power-on state (true/false)
• DefaultDirection: Power-on direction

Note: Changing PullType or PushType requires a chip reset.

Voltage Output Configuration

Each VIO_BANK channel:

• Range: 1.2V - 5.0V (values outside this range are clamped)
• Resolution: ~1.2 mV (12-bit DAC)
• Default: 1.8V

Register Bank Access

Register channels accept:

• Decimal: "42" → 0x2A
• Hexadecimal: "0x2A" → 42 decimal

Writing to a register bank updates all 8 GPIO pins in that port based on the bit pattern:

• Bit 0 → GPIO pin 0 (or 8)
• Bit 1 → GPIO pin 1 (or 9)
• ...
• Bit 7 → GPIO pin 7 (or 15)

Only OUTPUT-configured pins are updated; INPUT pins ignore register writes.

Programming Interface

Configure Individual GPIO:

ConfigureChannels(new[] {
    new DigitalChannel {
        NetName = "0.ESH10000025.GPIO00",
        Enabled = true,
        Direction = DirectionTypes.OUT,
        DefaultDirection = DirectionTypes.OUT,
        PullType = PullTypes.None,
        PushType = PushTypes.PushPull,
        Value = false
    }
});

Set Bank Voltage:

SetValues(
    new[] { "0.ESH10000025.VIO_BANK0" },
    new[] { "3.3" }  // 3.3V for Bank 0 (GPIO00-15)
);

Register Bank Write:

// Set GPIO00-07 to pattern 0b10101010 (0xAA)
SetValues(
    new[] { "0.ESH10000025.REGBANK_0A" },
    new[] { "0xAA" }  // or "170" in decimal
);

Best Practices

1. Set VIO voltage before enabling GPIO: Ensure correct logic levels before I/O operations
2. Use register banks for fast parallel operations: More efficient than individual GPIO writes
3. Configure pull types during initialization: Changing pull configuration requires chip reset
4. Group GPIO by voltage requirements: Assign similar logic levels to same bank
5. Enable channels before use: Always set Enabled = true in ConfigureChannels

Module Initialization Sequence

On Reset(), the module performs:

1. Clear existing channel list
2. Setup 6 VIO_BANK DAC channels with 1.8V default
3. Create 12 register bank channels (REGBANK_0A/B through REGBANK_5A/B)
4. Setup 6 GPIO expander chips (U6-U11) with 96 digital channels
5. Reset and configure all GPIO expanders
6. Update DAC with default voltage levels