8085 microprocessor doubts

Status
Not open for further replies.

vasanth kumar

Junior Member level 1
Joined
Jul 27, 2012
Messages
18
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Coimbatore
Visit site
Activity points
1,406
hello,
in microprocessor 8085, lower 8 bits of address bus is multiplexed with 8 bit bidirectional data bus in order to reduce the number of pins. but why there are seperate pins for read and write. why not they could not be given as read and write in a single pin by seperating them with active high and low signals respectively.
thanks......
 

hello,
in microprocessor 8085, lower 8 bits of address bus is multiplexed with 8 bit bidirectional data bus in order to reduce the number of pins. but why there are seperate pins for read and write.

Good question, the reason is simply "styles".
Many memories have (had) separate lines for R/W signal, however , many other devices have a single line for R/W operation.
The reason for separate R/W lines is, in my opinion, a good tradeoff for the capability of driving both kind of devices.
 
Its just a old kind of processor, and it was designed based on the usage of the peripherals then.
There are many kind of updates after. At that time they still haven't developed Micro-controller completely yet.
 

Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…