Hello all, Im having some trouble understanding some information. Please excuse my grammer .. English is my Second Language.

I am trying to interface a ADC0809 to my 8031. I have been looking around at some data sheets but had trouble understanding what they were trying to tell me. First of all i went here. http://www.learn-c.com/adc0809.pdf On page 12 it will show you a typical application. The part of this chip that confuses me is the START, ALE, and EOC. I understand that START is for when you want to start a conversion; so I believe i could put that to a bit on the 8031 and controll it by code (before i start a conversion), and EOC is End of conversion; and i read that this acts as if its a "clear flag" so i would be able to start a new conversion. Now the ALE .... I having trouble understanding what exactly this does, i know what an ALE does with the 8031 but do not think it works the same way with the A/D converter, i do not have luck finding information with this. I see that on page 7 of the data sheet i provided, i see that the ALE goes HIGH for an instance of time but then goes LOW. So is it controlled by the user (code) or can i just connect it to start so it goes HIGH when i start the conversion. I see that there was a Tutorial on 8052.com, but it did not help me much .. http://www.8052.com/users/bru...ematic.pdf, some pins from the 0809 are not listed there plus the LE might be the ALE not sure. i was thinking about what Page 7 does http://www.learn-c.com/adc0809.pdf. it shows a logic configuration. I believe what that does is when i want to read it enables the chip then when i want to write, it starts the conversion and enables the ALE.

Am i doing something wrong? or am i simply not reading hard enough?

this is my schematic of what exactly im doing





again thanks,


ED