Mbx821 002 (add page and link on Mbx8xx page)

CPU_model40MHz MPC82
NICs10BaseT Ethernet
SerialTwo additional EIA-232-D serial ports
OtherPC/104-Plus,EIDEnand Floppy interfaces,keyboard, mouse, IR, COM1 and COM2
PortsLCD panel connector


MBX series boards are a family of small form factor (5.75 × 8 inch) embedded controllers. They provide single-board computer functionality with emphasis on open communications and networking capabilities. They offer open interfaces such as PCI, ISA, and PCMCIA in addition to Ethernet and serial/parallel I/O. The features they incorporate make them well suited for embedded real-time applications in such areas as communications, industrial automation, and electronic imaging.

The MBX series has two parallel branches whose differences lie in the processor that powers them: one configuration is based on Motorola’s MPC821 embedded processor, while the other uses an MPC860 processor. The MPC860 version offers two additional serial communications controllers (SCCs) than the MPC821; the MPC821 version has an integrated LCD controller in their place. In other respects, the logic design is the same for both versions

As shown in the Features section, the MBX series embedded controller offers many standard features desirable in a computer system—such as synchronous and asynchronous serial ports, parallel port, boot ROM and DRAM, PCMCIA capability, Ethernet, support for external disk drives, and keyboard and mouse support—in a small, EBX form factor package. Its flexible mezzanine architect

Board Setup

MBX series embedded controllers have the capability to use 3.0V- 3.6V battery power (either on-board, or external via utility connector #1) as a backup power source for the ‘‘keep-alive’’ power circuits (such as the real-time clock) in the MPC8xx processor.

To select either battery source as the ‘‘keep-alive’’ power source, install a jumper across J1 pins 1 and 2. If no battery is installed, or if no backup is desired, place a jumper across pins 2 and 3 (the default for shipping and storage)

When you install a fresh backup battery on the MBX series embedded controller (or when you place a jumper across J1 pins 1 and 2), part of the procedure involves breaking the battery’s ‘‘freshness seal’’, i.e. initializing the keep-alive circuitr= Switches and LEDs =

The MBX board has provision for user-installed Abort and Reset switches and includes eight on-board LED (light-emitting diode) status indicators. The switches and six additional LED signals (five for Ethernet activity and one for an external hard disk drive) are available remotely via utility connector #1 (J16 on the MBX board)

ABORT Switch

When activated by software, the Abort switch can generate an interrupt signal to the MPC8xx processor at the IRQ7 level. The interrupt can be programmed as falling-edge active or as low-level active. The circuit is filtered for noise, to prevent false aborts.

RESET Switch

The Reset switch resets all onboard devices, including the PC/104, PC/104-Plus, and 8xx/COMM ports and the KAPWR (keep-alive power) circuits.

LED Indicators

There are eight status LEDs on the MBX board. As mentioned at the beginning of this section, six additional LED signals (five for Ethernet activity and one for an external hard disk drive) are available for external display via utility connector #1 (J16 on the MBX board). The LEDs on the board have the functions listed below


The MPC821 processor is especially well-suited for applications where lower power is essential, such as portable and/or highperformance communications systems. The CPU on the MPC821 is a 32-bit PowerPC™ implementation incorporating memory management units (MMUs) and instruction/data caches. It has a communications processor module that includes:

  • Two serial communication controller (SCC) channels
  • Two serial management channels (SMCs)
  • A serial peripheral interface (SPI) channel
  • an Interprocessor-Integrated Controller channel for data exchanges between the MPC821 and other ICs with I2C capability — microcontrollers, LCD displays,real-time clock devices, etc.The MPC821’s memory controller supports all available types of memory. Its PCMCIA controller supports up to two PCMCIA sockets (one is implemented on the MBX). There is also a display capability via LCD controller and a real-time clock

Cooling Requirements

The Motorola MBX series family of embedded controllers is specified, designed, and tested to operate reliably with an incoming air temperature range from 0? to 70? C (32? to 158? F) with forced air cooling of the entire assembly (base board and expansion modules) at a velocity typically achievable by using a 100 CFM axial fan. Temperature qualification is performed in a Motorola development chassis. Twenty-five-watt load boards are inserted in two card slots, one on each side, adjacent to the board under test, to simulate a high power density system configuration. An assembly of three axial fans, rated at 100 CFM per fan, is placed directly under the card cage. The incoming air temperature is measured between the fan assembly and the card cage, where the incoming airstream first encounters the module under test. Test software is executed as the module is subjected to ambient temperature variations. Case temperatures of critical, high power density integrated circuits are monitored to ensure component vendors’ specifications are not exceeded= References =

Last modified on Nov 7, 2018 at 12:10:19 PM Last modified on Nov 7, 2018, 12:10:19 PM