1.What is the purpose of the EA pin on the 8051? 2.What is...

Question by Eddy
Submitted on 2/13/2004
Related FAQ: 8051 microcontroller FAQ
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1.What is the purpose of the EA pin on the 8051? 2.What is the purpose of the ALE signal?How do you use this signal? 3.What is the purpose of the PSEN? 4.In a system with external memory, for what purpose are ports P0 and P2 used? 5.Does the stack grow toward higher or lower memory in the 8051? 7.At what address is the reset vector located in the 8051? What constraint does this impose on the addition of external memory for an 8031 which does not have internal ROM? 8.What interrupts are available on the 8051? 9.What memory locations do the interrupt vectors occupy, and why do you think the vectors are spaced at 8-byte intervals? 10.How many bytes of internal RAM are implemented in the 80C51? How about on the C501? Why is the inclusion of RAM on a microcontroller important? 11.If the first instruction of my code was PUSH ACC (or PUSH A), what memory address would contain the pushed copy of the accumulator? 12.For what purpose is DPTR used? 13.If I wanted to combine the external program and external data memory into one addressing space, what would I have to do to the PSEN and RD control signals? 14.In order to reset the processor, is it necessary to supply a logic high or a logic low voltage to the reset pin? Why is a reset signal required? What is the minimum voltage required on the RST pin to hold the processor in reset? What is the purpose of the diffused resistor inside the processor? 15.Review RC circuits. Now design an appropriate power on reset circuit for the 8051.

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Answer by chandu
Submitted on 1/9/2007
Rating: Not yet rated	Rate this answer:
if EA=vcc mc 1 st uses 0000h to 4k in 8051 after external 64k. EA=gnd it totally depends on external memory

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