04-10-2012, 03:58 PM
MICROPROCESSORS-8086
[attachment=35294]
MICROCOMPUTER
A MICROCOMPUTER SYSTEM IS ONE WHICH USES A MICROPROCESSOR AS ITS CPU
IN ADDITION THE MICROCOMPUTER ALSO HAS A MEMORY UNIT,INPUT/OUTPUT DEVICES AND SYSTEM BUSES.
THE SYSTEM BUSES ARE OF THREE TYPES: 1.ADDRESS BUS
2.DATA BUS
3.CONTROL BUS
ARCHITECTURE
THE INTERNAL ARCHITECTURE OF 8086 CAN BE MAINLY DIVIDED INTO TWO UNITS:
BUS INTERFACE UNIT (BIU)
EXECUTION UNIT (EU)
THE BIU CONTAINS :
CODE SEGMENT REGISTER (CS)
DATA SEGMENT REGISTER (DS)
EXTRA SEGMENT REGISTER (ES)
STACK SEGMENT REGISTEER (SS) AND
INSTRUCTION POINTER (IP)
READ CYCLE
HERE WE WILL SEE THE ACTIVITIES CARRIED OUT ON 8086 BUSES AT VARIOUS TIME INSTANTS WHEN IT READS FROM A MEMORY LOCATION OR FROM A PORT.
HERE WE WILL ASSUME THAT THE 8086 IS OPERATED IN IS MINIMUM MODE.
A SYSTEM ROM DECODER
TO UNDERSTAND THE CONCEPT A GENERAL DIGITAL SYSTEM WITH 8 DATA LINES AND 16 ADDRESS LINES IS CONSIDERED.
A SYSTEM RAM DECODER
TO THE SAME SYSTEM WE WANT TO ADD 16KB RAM.SO ADDITIONAL HARDWARE WE REQUIRE:
SINCE WE HAVE EACH RAM OF 2KB(2048 BYTES) ,WE NEED 11 ADDRESS LINES TO ADDRESS EACH MEMORY LOCATION WITHIN A RAM.AS WE HAVE OCCUPIED ADDRESSES 0000 THROUGH 7FFF FOR ROM.WE MUST START RAM ADDRESSES AFTER 7FFF.
[attachment=35294]
MICROCOMPUTER
A MICROCOMPUTER SYSTEM IS ONE WHICH USES A MICROPROCESSOR AS ITS CPU
IN ADDITION THE MICROCOMPUTER ALSO HAS A MEMORY UNIT,INPUT/OUTPUT DEVICES AND SYSTEM BUSES.
THE SYSTEM BUSES ARE OF THREE TYPES: 1.ADDRESS BUS
2.DATA BUS
3.CONTROL BUS
ARCHITECTURE
THE INTERNAL ARCHITECTURE OF 8086 CAN BE MAINLY DIVIDED INTO TWO UNITS:
BUS INTERFACE UNIT (BIU)
EXECUTION UNIT (EU)
THE BIU CONTAINS :
CODE SEGMENT REGISTER (CS)
DATA SEGMENT REGISTER (DS)
EXTRA SEGMENT REGISTER (ES)
STACK SEGMENT REGISTEER (SS) AND
INSTRUCTION POINTER (IP)
READ CYCLE
HERE WE WILL SEE THE ACTIVITIES CARRIED OUT ON 8086 BUSES AT VARIOUS TIME INSTANTS WHEN IT READS FROM A MEMORY LOCATION OR FROM A PORT.
HERE WE WILL ASSUME THAT THE 8086 IS OPERATED IN IS MINIMUM MODE.
A SYSTEM ROM DECODER
TO UNDERSTAND THE CONCEPT A GENERAL DIGITAL SYSTEM WITH 8 DATA LINES AND 16 ADDRESS LINES IS CONSIDERED.
A SYSTEM RAM DECODER
TO THE SAME SYSTEM WE WANT TO ADD 16KB RAM.SO ADDITIONAL HARDWARE WE REQUIRE:
SINCE WE HAVE EACH RAM OF 2KB(2048 BYTES) ,WE NEED 11 ADDRESS LINES TO ADDRESS EACH MEMORY LOCATION WITHIN A RAM.AS WE HAVE OCCUPIED ADDRESSES 0000 THROUGH 7FFF FOR ROM.WE MUST START RAM ADDRESSES AFTER 7FFF.