8086 Records Essay

Microprocessors and Microcontrollers/Interfacing with 8086

Notes from a class

Module a few Learning device 8: User interface

• • • • • • • • • We have four common types of memory: Browse only recollection (ROM) Flash memory (EEPROM) Static Unique access recollection (SARAM) Dynamic Random gain access to memory (DRAM). Pin links common to every memory gadgets are: The address type, data output or input/outputs, selection type and control input accustomed to select a go through or publish operation. Address connections: Every memory gadgets have treat inputs that select a recollection location within the memory gadget. Address inputs are marked from A0 to An. Info connections: Every memory equipment have a couple of data results or input/outputs. Today many of them have bi-directional common I/O pins. Selection connections: Every memory device has an suggestions, that selects or enables the recollection device. This sort of input is quite often called a chip choose ( CS ), processor chip enable ( CE ) or simply select ( S ) input.





A1 A2








MEMORY PART ILLUSTRATING THE ADDRESS, DATA AND, CONTROL CONNECTIONS • • RAM memory generally has in least one CS or perhaps S input and RANGE OF MOTION at least one VOTRE. If the CE, CS, S input is definitely active the memory unit perform the read or perhaps write.

M. Krishna Kumar/IISc. Bangalore

M3/V1/June 04/1

Microprocessors and Microcontrollers/Interfacing with 8086

Lecture Notes

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If it is non-active the storage device simply cannot perform browse or create operation. If more than one CS connection is present, all the majority of be active to perform browse or write data. Control connections: A ROM usually has only one control input, while a RAM often has a few control advices. The control input most often found on the ROM is the end result enable ( OE ) or gateway ( G ), this permits data to flow from the output info pins with the ROM. In the event OE as well as the selected type are both effective, then the outcome is enable, if FACTORY is inactive, the output is usually disabled at its high-impedance state. The OEM connection allows and hinders a set of three-state buffer located within the memory space device and must be effective to read data. A MEMORY memory unit has both or two control inputs. If you have one control input it is usually called R/ W. This pin selects a browse operation or maybe a write operation only if the device is selected by the variety input ( CS ). If the RAM has two control inputs, they are usually branded WE or W and OE or G. ( WE ) write permit must be energetic to perform a memory create operation and OE must be active to accomplish a memory read operation. When the two of these controls ALL OF US and OEM are present, they must never be active as well. The ROM read just memory completely stores programs and info and data was usually present, even though power can be disconnected. It is also called because non-volatile recollection. EPROM (erasable programmable examine only memory) is also erasable if confronted with high intensity ultraviolet (uv) light for approximately 20 minutes or less, depending upon the kind of EPROM. We have PROM (programmable read only memory) RMM (read mainly memory) is additionally called the flash recollection. The flash memory is likewise called as an EEPROM (electrically erasable programmable ROM), EAROM (electrically alterable ROM), or a NOVROM ( non-volatile ROM). These kinds of memory equipment are electrically erasable in the system, although require additional time to erase than a typical RAM. EPROM contains the series of 27XXX provides the following part numbers: 2704(512 * 8), 2708(1K * 8), 2716(2K * 8), 2732(4K * 8), 2764(8K 5. 8), 27128(16K * 8) etc . Each of these parts consists of address hooks, eight data connections, more than one chip variety inputs ( CE ) and a great output permit pin ( OE ). This device is made up of 11 address inputs and 8 info outputs. In the event both the pin number connection CE and FACTORY are at common sense 0, info will appear around the output connection. If both pins are generally not at reasoning 0, the information...