Why do we need multiplexed address data lines in 8085?
Multiplexing is used to reduce the number of pins of 8085, which otherwise would have been a 48 pin chip. But because of multiplexing, external hardware is required to demultiplex the lower byte address cum data bus. ALE signal is used to demultiplex the lower order address bus (AD0 – AD7).
Why is Adm demultiplexing required for AD7 lines?
As AD7-AD0 lines serve a dual purpose they have to be demultiplexed to get all the information. The address’s high order bits remain on the bus for 3 clock periods. An external latch is used to save the value of AD7-AD0 when it is carrying the address bits so that the entire address remains for the 3 clock cycles.
Why the part of address lines are multiplexed with data lines in 8085 or 8086 how the stable address and data bus without multiplexing is achieved?
8085: The main reason of multiplexing address and data bus is to reduce the number of pins for address and data and dedicate those pins for other several functions of microprocessor. These multiplexed set of lines used to carry the lower order 8 bit address as well as data bus.
Why do we Demultiplex AD0 to AD7 of 8085 microprocessor design and explain appropriate demultiplexing circuit?
Demultiplexing of AD0-AD7 using IC 74LS373 Cons of multiplexing of pins in a microprocessor: We need additional circuitry to demultiplex these pins to allow them to serve their multiple purposes individually. But for extracting the data and the lower 8 bits of the address, we demultiplex AD0-AD7 using IC 74LS373.
How is demultiplexing done?
In this approach, the demultiplexing is done one wavelength at a time. The demultiplexer consists of W filter stages in series, one for each of the W wavelengths. Each filter stage demultiplexes a wavelength and allows the other wavelengths to pass through.
Why is demultiplexing needed?
The address’s high order bits remain on the bus for 3 clock periods. The low order bits remain for only 1 clock period and may be lost if they are not saved externally. Therefore this Bus needs to be the Demultiplexed so that the necessary information (whether address or data) can be accessed accordingly.
What does a demux do?
A demultiplexer (also known as a demux or data distributor) is defined as a circuit that can distribute or deliver multiple outputs from a single input. A demultiplexer can perform as a single input with many output switches.
What is the necessity of demultiplexing of lower data bus Explain with diagram?
Therefore this Bus needs to be the demultiplexed so that the necessary information (whether address or data) can be accessed accordingly. A Latch is used in order to separate address from the data and also to save the address value before the change of the bits occur.
What do you mean by bidirectional data bus?
[‚bī·də′rek·shən·əl ′dad·ə ‚bəs] (computer science) A channel over which data can be transmitted in either direction within a computer system.
Which bus is called bidirectional and why?
Data bus is Bidirectional because the Microprocessor can read data from memory or write data to the memory.
Which is the world’s first microprocessor?
Early manufacturing. The first Intel® 4004 microprocessor was produced on two-inch wafers compared to the 12-inch wafers commonly used for today’s products. The Intel 4004 microprocessor is unique in that it is one of the smallest microprocessor designs that ever went into commercial production.