Principle and application of single chip microcomputer - off chip development

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One 、51 Minimum system of single chip microcomputer

In the film ROM Chip minimum system construction ：

No on-chip ROM Chip minimum system construction ：

Single chip external bus expansion ：
To prevent short circuit of bus equipment , The external chip needs a chip selection port CS.

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Two 、51 Single chip microcomputer off chip bus expands memory

No matter what memory chip it is , The pins should be connected with the chip three bus .
1） Control line ：
Program memory ：ROM The chip output allows the control line OE With the monolithic PSEN Signal line connection .
Data storage ：RAM The chip output allows the control line OE And write control lines WE Read signal lines with MCU respectively RD And signal line WR Connect .

3、 ... and 、 parallel IO Mouth expansion

Absolute address access

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