Address/data buffers in 8085 Microprocessor

Address and data buffers are used for bidirectional data transfer. They perform the unidirectional data transfer when they send out the Least Significant Byte of the address. These buffers are only used for increasing the driving capacity of the current. Through the internal bus data goes to the buffers. The Least Significant Byte of the address goes to the buffers from the internal address latch to the other.

Hence the address or data are sent out on the address ranging from AD₇ to AD0 can drive every external chips, like chips of RAM, chips of EPROM, and other peripheral chips meant for carrying the work. Likewise, all the data received by the 8085 microprocessor from the outside is also buffered internally. The data on the range of address ranging from AD₇ to AD0 also reaches to the internal bus, from where the final destination is reached.

In fact, also in a practical microcomputer system, the driving capacity for the data pins, after the internal buffering procedure, might not be satisfactory. So there will always be external buffer chips to carry out the entire work.

Address buffers: These buffers are meant for unidirectional transfer of schematic addresses which are only used for sending out the Most Significant Byte of the given address. The Most Significant Byte of the address goes to the buffers from the address latch internally. Hence the address sent out to the range of address ranging from AD15 to AD7 drives all the external chips, like chips of RAM, chips of EPROM, and other peripheral chips.

Obviously in a practical microcomputer system, the driving capacity of the address pins, after the internal buffering, might not be satisfactory. So there must be external buffer chips to carry out the work.