Overall Document:

This document is a datasheet (technical specification sheet) for the "GL641USB" chip, a USB controller targeted for use with storage devices, particularly Compact Flash cards and ATA/ATAPI devices. It details the chip's functionality, pin assignments, and general operational characteristics.

Key Sections and Their Contents:

️· Introduction & Block Diagram (Figure 2-1): The chip's purpose is to act as a bridge between a USB host and a storage device. The block diagram shows the basic architecture, including data buses, registers, control logic, and USB interface elements.
️· Pin Definitions and Descriptions (Table 3-1): This is the most important section for engineers using the chip. It lists *every* pin on the chip, its name (e.g., PVDD, D0, GPIO1), whether it's an input (I), output (O), or bidirectional (I/O), and a brief explanation of its function. Crucially, it explains the power and voltage requirements for various pins.
️· General Purpose I/O Ports: This section explains the function of GPIO pins (GPIO1-GPIO8). For example:
- GPIO1: Used to determine whether the attached device is a CompactFlash card or an ATA/ATAPI device (strapping pin).
- GPIO2: Power control for bus-powered devices (important for CompactFlash card management).
- GPIO3: Connection for an external reset signal for ATA/ATAPI/CompactFlash cards.
- GPIO4-GPIO7: Used for interfacing with a serial EEPROM to store vendor ID and product ID information.
- GPIO8: Used as a card detection signal for CompactFlash cards.
️· Package Diagram: Shows the physical layout of the chip's package (a 48-pin LQFP - Low-Profile Quad Flatpack). It includes dimensions and tolerances.

Key Technical Points & Characteristics:

️· USB Controller: Designed to act as a USB interface for storage devices.
️· Storage Device Compatibility: Supports Compact Flash, ATA/ATAPI, and other storage interfaces.
️· Power Management: Includes pins for supplying power to the storage device and controlling its power state (GPIO2).
️· Configuration: GPIO1 is used to configure the chip's mode of operation.
️· EEPROM Interface: GPIO pins (4-7) allow for programming a serial EEPROM for storing device identification data.
️· Package: 48-pin LQFP
️· Operating Voltage/Power: Details are on different power pins (V3.3, DVDD, AVDD).
️· Signal Types: A mix of power, data, control, and general-purpose I/O pins.



Important Notes:

️· "BSC" Dimension: This abbreviation (BSC) means "basic" and refers to a dimension that is specified without tolerances.
️· Output Voltage: The datasheet notes that output voltages on certain pins are related to the power supply voltage (PVDD), so proper voltage levels are required for proper operation.
️· Signal Levels: The document mentions 3.3V and 5V power supply requirements.
️· STRAPPING PIN: GPIO1 is a Strapping Pin which is used during startup to define the operational mode of the chip.



Who is this document for?

This datasheet is intended for hardware engineers, embedded systems developers, and anyone who needs to integrate the GL41USB chip into a hardware design.