PDIUSBD12 Structure, Pin Configuration, Characteristics and Applications
16 January 2024
Ⅲ. Internal structure of PDIUSBD12
Ⅳ. Pin configuration of PDIUSBD12
Ⅴ. What are the characteristics of PDIUSBD12?
Ⅶ. What are the applications of PDIUSBD12?
PDIUSBD12 is a performance optimized and affordable USB device. It is typically used in microcontroller-based systems and communicates with the microcontroller through a high-speed general-purpose parallel interface while supporting local DMA. In this article, we will introduce the characteristics and applications of PDIUSBD12 to help you better understand this chip and provide strong support for embedded system design.
PDIUSBD12 is a USB interface chip manufactured by NXP Semiconductors (formerly Philips Semiconductors). This chip seamlessly integrates with microcontroller units through a 8-bit parallel data line, complemented by a discerning 1-bit address line adept at distinguishing between write commands and read or write data operations. The sophistication of the PDIUSBD12 is further underscored by its support for three USB endpoints. Notably, one of these endpoints exhibits a storage capacity of 128 bytes, while the remaining two endpoints elevate their capability with 256-byte storage capacity each. With a total of 28 pins, the PDIUSBD12 exemplifies a harmonious amalgamation of precision and versatility in USB interface technology.
The low power consumption of the PDIUSBD12 when hung and the LazyClock output meet the requirements of ACPI, OnNOW and USB power management devices. The low-power operation allows the implementation of bus-powered peripherals. In addition, the PDIUSBD12 integrates features like SoftConnect, GoodLink, programmable clock outputs, low frequency crystals and termination resistors. All of these features provide cost savings in system implementation while making it easy to implement more advanced USB functionality in peripheral devices.
The PDIUSBD12 is fully compliant with the USB 1.1 and USB 2.0 full-speed specifications, and can also be designed to accommodate most device class specifications such as imaging, communications, printing, mass storage, and manual input devices. Therefore, PDIUSBD12 is very suitable for many peripheral devices, such as scanners, printers, external mass storage (Zip drive) and digital cameras.
The internal structure of PDIUSBD12 is shown below.
1. PLL: It integrates a 6 MHz to 48 MHz frequency multiplier phase locked loop (PLL) on-chip, allowing the use of a 6 MHz crystal oscillator. At the same time, EMI is also reduced due to the use of low-frequency crystal oscillators. No external components are required for the operation of the PLL.
2. GoodLink: GoodLink relies on a pin to connect a light-emitting diode. When the USB device is enumerated, the LED indicator light will flash immediately; when the PDIUSBD12 is successfully enumerated and configured, the LED indicator light will always be on; during the USB data transmission process through the PDIUSBD12, the LED will flash one after another, indicating that the transmission is successful. After the LED goes off; during suspend, the LED goes off. This feature allows us to know the status of PDIUSBD12 and facilitate circuit debugging.
3. Bit clock recovery: The bit clock recovery circuit uses the 4x oversampling principle to recover the clock from the input USB data stream and is able to track the signal jitter and frequency drift pointed out in the USB specification.
4. Analog transceiver: The integrated transceiver interfaces directly with the USB cable through the termination resistor.
5. Memory management unit MMU and integrated RAM: MMU and integrated RAM can buffer the speed difference between USB (operating at 12Mb/s) data transfer and the parallel interface between the microcontroller, which allows the microcontroller to read at its own speed write USB package.
6. SoftConnect: The connection between high-speed devices and USB is established by connecting D+ to a high level through a 1.5kΩ pull-up resistor. In PDIUSBD12, this pull-up resistor is integrated in the chip and is not connected to Vcc by default. This connection is established by sending a command from the external MCU. This allows the system microprocessor to complete initialization before deciding to establish a USB connection. Reinitializing the USB bus connection can also be done without unplugging the cable.
7. Voltage regulator: A 3.3V voltage regulator integrated on the chip supplies power to the analog transceiver and also provides an output voltage connected to an external 1.5kΩ pull-up resistor. As an option, PDIUSBD12 offers SoftConnect technology with integrated 1.5kΩ pull-up resistor.
8. Parallel and DMA interface: The parallel interface is easy to use, fast and can interface directly with the main microcontroller. For microcontrollers, PDIUSBD12 can be regarded as a storage device with an 8-bit data bus and a 1-bit address line. PDIUSBD12 supports multiplexed and non-multiplexed address and data buses. It can also use DMA (Direct Memory Access) transfers between the main endpoint (Endpoint 2) and local shared memory. It supports two DMA transfers, single cycle mode and block transfer mode.
9. PHILIPS serial interface engine PSIE: PHILIPS’ SIE fully implements the USB protocol layer. Considering speed, it is all hardware and does not require firmware (microprogram) intervention. Functions of this module include synchronization pattern recognition, parallel/serial conversion, PID confirmation, CRC check, bit stuffing/non-stuffing, address recognition, and handshake identification.
• Easy to Integrate: The chip is designed to be easily integrated into a variety of devices such as embedded systems, peripherals, and more.
• USB 2.0 compatibility: The PDIUSBD12 is compatible with the USB 2.0 standard, facilitating high-speed data transfer that significantly enhances the effectiveness and reliability of data communication.
• Support USB standard device descriptor: PDIUSBD12 supports USB device descriptor. This is a very important data structure used to provide information about USB devices to the operating system to help the operating system correctly identify and configure connected USB devices.
• Supports multiple transfer rates: In addition to high speed mode, the chip also supports full speed (12 Mbps) and low speed (1.5 Mbps) USB transfer rates. This means that users can choose the right transfer speed for different application scenarios according to their needs.
• Integrated power management: Integrated power management features in the chip optimize power consumption and prolong battery life, assisting users in efficiently managing power and enhancing energy efficiency, thereby extending the lifespan of electronic devices.
• Low power consumption: To meet the requirements of portable devices and low power applications, the PDIUSBD12 is typically designed with low power consumption features.
• Integrated controller functionality: The PDIUSBD12 is a chip with integrated USB controller functionality that features a high degree of integration and efficient performance. This chip can help simplify connection and communication with the USB bus while providing a faster and more stable communication interface.
The PDIUSBD12 endpoints exhibit the versatility to accommodate a variety of device classes, including Imaging, Printer, Mass Storage, and Communication device classes. Configurable through the set mode command, these endpoints offer four operating modes, namely:
Mode 0: Non-isochronous transfer (Non-ISO mode)
Mode 1: lsochronous output only transfer (ISO-OUT mode)
Mode 2: lsochronous input only transfer (ISO-IN mode)
Mode 3: lsochronous input and output transfer (ISO-l/O mode)
PDIUSBD12 is mainly used in the following fields:
• Multimedia applications: The chip is suitable for various multimedia applications such as audio transmission, video capture and playback. By connecting the corresponding multimedia devices, PDIUSBD12 can realize high-speed, high-quality multimedia data transmission and playback functions.
• Embedded system development: The chip is designed for the development of embedded systems, allowing developers to establish communication and control with microcontrollers and peripherals via the USB interface. This streamlines the design and debugging phases of embedded systems, ultimately enhancing development efficiency.
• Data transfer and communication: The chip can be used as a high-speed USB communication interface for data transfer and communication between various devices. For example, it can be connected to devices such as scanners, cameras and printers for high-speed data transfer and real-time communication.
• Control and debugging of USB devices: PDIUSBD12 can be used as an interface to control and debug USB devices. Through firmware programming and the writing of customer applications, PDIUSBD12 can provide functions such as control, status monitoring and debugging of USB devices.
• Portable devices: Due to its low power consumption and miniaturization, the PDIUSBD12 is well-suited for numerous portable devices, including digital cameras, cell phones, tablet PCs, and more. Within these devices, the PDIUSBD12 can function as a power-efficient USB interface, facilitating data transmission and charging capabilities between the device and a computer.
