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The control signals in an 8085 are already generated. They are CLK, S0, S1, ALE, RD-, WR-, IO/M-, INTA-, HLDA, SOD, and RESET OUT. The only control signal that needs to be generated in a medium to large bus organization is DATAENEABLE-. This is optional, if the external logic is compatible but, if not, it needs to be generated from ALE, S1, and CLK, in order to properly drive the data bus buffers without encountering a race condition during WR-. Basically, DATAENABLE- is equal to (RD- when ALE is low) if S1 is high, and it is equal to ALE if S1 is low.
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∙ 13y ago
Wiki User
∙ 12y agoThe control signals of the 8085 are CLK, ALE, S0, S1, IO/M-, RD-, WR-, HOLD, HLDA, and READY.
Wiki User
∙ 14y agoMERD-Memory read MEWR- Memory write IORD-input output read IOWR-Input output write
Wiki User
∙ 10y agoControl signal used by 8085 micro-processer is a cable that holds up to 64K of memory. The micro-processer has 40 pins and 5 volts.
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∙ 13y agoRd" and wr"
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What is the function of CLKOUT pin in microprocessor 8085?
The CLK signal in the 8085 is the system clock, which is the External Input Frequency or Crystal divided by two. It can be used to develop bus control logic, because it is essentially the inverse of ALE for one half clock cycle.
What is the signal used for DMA in 8085?
The HOLD pin indicates that an external device wants the 8085 to stop and allow the external device to drive the bus. The acknowledge of control transfer is HLDA, however, it is important to note that HLDA does not mean the current cycle is complete - it means that the current cycle is the last cycle, at which point the 8085 will release the bus. (One half clock cycle later.)
What is bus in 8085?
there are mainly 3 buses are there in 8085. They are: Address bus :-Used to carry address Data bus :- Used to carry data Control bus :-Used to carry signals such as control and timing signals
What are the pins used to control interrupts?
The pins used to control interrupts in the 8085 are INTR/INTA, RST5.5, RST6.5, RST7.5, and TRAP.
Basic DMA operation and 8237 DMA Controller?
In the 8085, DMA (Direct Memory Access) is controlled with HOLD and HLDA. The HOLD signal is a request to release the bus. The HLDA signal is the 8085's acknowledgement of that request. HLDA means that the 8085 will release the bus in one half clock cycle, i.e. at the end of T3. The 8085 will remain in that hold state until HOLD is released, at which point it will take control of the buses again. The HOLD'ing device has complete control and can access any memory or I/O. Often, the 8237 DMA controller is used to provide sequencing of the operation. The 8237 DMA controller interfaces between up to four peripheral devices and the 8085. It provides an address register for each device so that the device does not need to do so. The device only needs to indicate that a byte of data is available, or is required, and the 8237 will take care of storing or fetching the byte.
Why you use RST5 in place of halt in Intel 8085?
RST 5 is used in place of HLT in the Intel 8085 kit in order to return control to the monitor program. If HLT were used, the processor would stop and so would the monitor.
What is the basic function of RESET signal in 8085 microprocessor?
Reset In:A low on this pin 1)Sets the program counter to zero. 2)Resets the interrupt enable and HLDA flip-flops. 3)Tristates the data bus,address bus nd control bus. 4)Affetcs the contents of processor's internal registers randomly. Reset Out:This active high signal indicates that processor is being reset.This signal is synchronized to processor clock nd ir can be used to reset other devices connected in the system ---BalaG Mulate---
What is the Intel 8085?
Intel 8085 is a microprocessor that is used in various electronics devices.
What are the application of 8085 microprocesser?
The Intel 8085 was the successor of the 8080, an early 8 bit processor, used most famously in the Altair. (Microsoft wrote Microsoft BASIC for the 8085 Altair). The boom of home computers took off with the Zilog Z80, a compatible processor but had more features. Today the 8085 isn't used much commercially, the 8051 is a more common 8 bit processor for embedded systems. However the 8085 is extremely popular in engineering schools in the middle east, especially India, as an introductory course to microcomputers.
What power supply is used in microprocessor 8085 programming?
+5v necessary for microprocessor 8085.
A traffic sign which is used to control traffic is called a what?
traffic signal.
What is function of hold pin in 8085 microprocessor?
The HOLD pin on the 8085 is an external request for control of the bus. Upon receipt of HOLD, the 8085 will complete its current cycle and assert HLDA (HOLD Acknowledge), and then it will float the address, data, and control bus one half clock cycle later. The external hardware is then free to use the bus. When it is done, it releases HOLD, the 8085 releases HLDA, and the 8085 takes control of the bus and continues with the next cycle. HOLD is used by external DMA controllers, such as the 8257, to transfer data to and from memory on behalf of high speed peripherals, without requiring 8085 attention to that data transfer.
