Motorola MBX Series, Installation And Use Manual

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Functional Description
5
Interprocessor-Integrated Controller (I
2
C) channel for data exchanges
between the MPC860 and other ICs with I
2
C capability. The MPC860’s
memory controller supports all available types of memory. Its PCMCIA
controller supports up to two PCMCIA devices (one socket is provided on
the MBX).
MPC821
The MPC821 processor is especially well-suited for applications where
lower power is essential, such as portable and/or high-performance
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 real-time clock and a communications
processor module that includes serial communication controllers, serial
management controllers, a serial peripheral interface (SPI) channel, and an
Interprocessor-Integrated Controller (I
2
C) channel for data exchanges
between the MPC821 and other ICs with I
2
C capability. The MPC821’s
memory controller supports all available types of memory. Its PCMCIA
controller supports up to two PCMCIA devices (one socket is provided on
the MBX). The MPC821 also incorporates an LCD controller for display
capability.
Real-Time Clock/Timer Functions
The processor chip used on MBX series embedded controllers
incorporates a clock module to provide the various system clock and timer
functions as well as low power control circuitry for the system. Among the
outputs of the clock module is a real-time clock (RTC). The real-time clock
provides a time-of-day indication to the operating system and to
application software.
The clock is unaffected by Reset signals and operates in all low-power
modes. It can be programmed to generate a maskable interrupt via an alarm
register. The RTC furnishes seconds, minutes, hours, day, month, and year
in BCD 24-hour format. Corrections for 28-, 29- (leap year), and 30-day
months are made automatically.