The SPU has a read channel for receiving a single data word from the mailbox and two write channels for sending data words (more on this below).

SPU有一个读通道来从邮箱接收单个数据字，有两个写通道来发送数据字(更详细的介绍请参看下文)。

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This paper describes a multiplexer which can multiplex two channels of data. It adopts asynchronous serial communication mode, USES Single chip CPU-89C51 and other IC chips to realize the function.

本文探讨的是一个两路的数据复用器，该数据复用器采用异步串行通信方式，主要用89c5 1单片机来实现。

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