ADLINK cPCI-3720: 3U CompactPCI Low Power Pentium III CPU Module

ADLINK cPCI-3720: Technical Analysis of 3U CompactPCI Low Power CPU Module Based on Mobile Pentium III

In the fields of industrial control, telecommunications infrastructure, military electronics, and transportation, the CompactPCI (cPCI) bus platform has long been an ideal choice for building critical mission systems due to its robust Eurocard mechanical structure, excellent heat dissipation performance, highly reliable connector design, and redundant power support on the backplane. With increasingly stringent requirements for power consumption, heat dissipation, and spatial layout in the system, the 3U CompactPCI (100mm × 160mm) specification occupies an important position in many applications due to its compact size and flexible configuration.

The ADLINK cPCI-3720 series 3U CompactPCI low-power CPU module is designed specifically for this type of application. It is based on the Mobile Intel Pentium III processor and Intel 440MX chipset, achieving complete x86 PC functionality in a compact 3U space while controlling power consumption at an extremely low level. Its flexible slot configuration (1 slot/2 slots/3 slots), dual 10/100Mbps Ethernet, configurable serial port, and hot swappable support make it an ideal choice for embedded applications with strict requirements for power consumption, heat dissipation, and reliability, such as telecommunications access equipment, railway signal control, and military data acquisition systems.

Overview of Product Positioning and Hardware Architecture

The cPCI-3720 series is a 3U CPU module that fully complies with the PICMG 2.0 Rev. 3.0 CompactPCI specification, with dimensions of 100mm × 160mm. It is designed as the system slot main control CPU, but also supports running in peripheral slots (without occupying CompactPCI bus communication). This series offers multiple model variants to meet the performance, storage, and space requirements of different application scenarios:

Model Slot Width Processor Built in Storage Applicable Scenarios

CPCI-3720A/P72 1 slot (4HP) Pentium III 700MHz CompactFlash (via mezzanine card) ultra compact, low-power, no mechanical hard drive application

CPCI-3720A/C42 1 slot (4HP) Celeron 400MHz CompactFlash (via mezzanine card) cost sensitive, low-power applications

CPCI-3720B/P72 2-slot (8HP) Pentium III 700MHz 2.5 "ATA HDD+CompactFlash for mainstream applications requiring large capacity local storage

CPCI-3720B/C42 2 2 Slot (8HP) Celeron 400MHz 2.5 "ATA HDD+CompactFlash Cost Sensitive+Local Storage Requirements

In addition, with additional mezzanine card support, it can be expanded to a width of 3 slots (12HP) to accommodate devices such as ultra-thin floppy drives (FDD).

1. Processor and chipset: the essence of low-power mobile platforms

The cPCI-3720 series uses Intel Mobile Pentium III BGA2 processor (0.18-micron process) or Mobile Celeron processor, which is a low-power version designed specifically for mobile computing and runs at a much lower voltage than desktop processors. Main parameters:

Pentium III 700MHz: 100MHz FSB, 256KB on-chip full speed L2 cache, suitable for applications that require higher integer and floating-point performance.

Celeron 400MHz: 100MHz FSB, 128KB on-chip full speed L2 cache, cost-effective option.

Chipset: Intel 440MX, which is a highly integrated chipset designed by Intel for mobile and embedded platforms. It integrates northbridge and southbridge functions into a single chip, significantly reducing power consumption and PCB area.

2. Memory support

Equipped with a 144 pin SO-DIMM slot, supporting PC-100 SDRAM with a maximum capacity of 256MB. The memory type must be 3.3V SDRAM. This capacity is sufficient to meet the majority of task requirements for running lightweight embedded operating systems (such as Windows NT/2000, VxWorks, QNX, embedded Linux) and control applications. ADLINK provides OEM bulk pre installed memory services.

Deep analysis of key characteristics

1. Flexible network configuration: Dual Intel 82559 Ethernet controllers

CPCI-3720 provides two Intel 82559 Fast Ethernet Multifunction PCI Controller 10/100BaseTx Ethernet channels. 82559 integrates MAC and PHY into a single chip, making it a mature, reliable, and widely driven industrial grade Ethernet controller.

LAN1: Only supports front panel I/O (RJ-45 interface).

LAN2: Supports front and back panel I/O (via cPCI-R3720 RTM), and selects whether LAN2 signals are routed to the front or back panel through onboard DIP switches (S2 and S3). The front and rear panels cannot use LAN2 simultaneously.

The dual port design supports network redundancy (such as link aggregation) or physical isolation between the management network and the data network, making it suitable for application scenarios that require high reliability communication (such as telecommunications billing systems, remote monitoring gateways).

2. Rich serial interfaces and configurability

CPCI-3720 provides two 16C550 UART compatible serial ports:

COM1: Only lead out to the DB-9 interface through the J2 rear wiring connector (cPCI-R3720). Through the jumper wires (JP1-JP4) on cPCI-R3720, COM1 can be configured as: