用PLDs(5C032,5C060)设计一个邮箱实现两个80

Very often, complex systems involve two or more microcontrollers to fulfill the requirements defined by a given objective. Since the nature of microcontrollers
does not allow for easy dual-port memory design (no``READY'' input; no ``HOLD/HLDA'' interface; portoriented I/O etc.), design engineers are faced with the problem of interchanging information (data and status) between those microcontrollers. This application brief describes the design of a mailbox for exchanging information
between two 80C31s, using a 5C060 PLD as a ``back-to-back'' register, and a 5C032 PLD as an arbitration vehicle to control the actions of the CPUs.
CONTENTS PAGE
INTRODUCTION  1
5C060 MAILBOX  1
5C032 MAILBOX CONTROLLER  2
Block Diagram  3
5C060 ``Back to Back Register''  4
5C032 ``Mailbox Controller''  5
5C060 Register ADF  6
5C032 Arbiter ADF  7