# UsbOcUpdateDxeCLX64L
**Index**: 0060 | **Size**: 5696 bytes | **Arch**: x64 | **Phase**: DXE

## Overview
USB Overcurrent (OC) pin mapping DXE driver for the CLX64L platform. Determines PCH stepping via MMIO PCI config space (LPC DID register), then selects the appropriate USB OC pin mapping table through the UBA protocol. Supports stepping decode from A0 through D0 with different pin count mappings (48-pin vs 54-pin).

## Key Functions
- `UsbOcUpdateCallback` -- Callback invoked by UBA protocol to select the OC table based on PCH stepping
- `UsbOcUpdateGetPchStepping` -- Decodes PCH stepping by reading VID/DID + SUBVID registers and revision
- `MmPciRead16` -- MMIO PCI configuration space read via MM PCI Base protocol

## Protocols / Dependencies
- UBA USB OC Update Protocol
- MM PCI User Space Register Area (MmPciBase)
- PCH LPC device at B:D:F 0:0:0, offset 0x48 for USRA base

## Platform
HR650X, PCH stepping decode (A0-D0, 0xA13F-0xA14C DID range), USB OC table selection