I never heard of that ?

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??? 04/26/08 07:01 Read: times	#154002 - I never heard of that ? Responding to: ???'s previous message
	Yes it is. If you see the datasheets of 2 Wire interface EEPROMs, you can find that SDA line is open drain(which works as tristate) and it requires external pullup. And most of the controllers i had used(including ARM7) provide open drain pins for I2C lines.

List of 33 messages in thread

Topic Author Date
about port 0 0f 8051mc              01/01/70 00:00
   already answered              01/01/70 00:00
      P0 pullups              01/01/70 00:00
         Tristate (pedant mode)              01/01/70 00:00
         This thread turns to helter-skelter              01/01/70 00:00
         I never heard of that              01/01/70 00:00
            I never heard of that ?              01/01/70 00:00
            I never heard of that ?              01/01/70 00:00
               Tristate (pedant mode, again)              01/01/70 00:00
                  three states              01/01/70 00:00
                     not at all confusing              01/01/70 00:00
               confusing open drain/collector with tristate ...              01/01/70 00:00
                  Not quite true              01/01/70 00:00
                     much 'can' be done              01/01/70 00:00
   read the datasheet ... it is "open-drain"              01/01/70 00:00
      advantage              01/01/70 00:00
         that it is not clogged              01/01/70 00:00
            or a wire-or-ed output              01/01/70 00:00
               ????              01/01/70 00:00
         How would you realize an input /output topology?              01/01/70 00:00
            why              01/01/70 00:00
               this is the diagram of the "inside" of chip              01/01/70 00:00
            please comment              01/01/70 00:00
               1) Maybe, 2) False, 3) False              01/01/70 00:00
               FAQ              01/01/70 00:00
               Have you read at all what I wrote??              01/01/70 00:00
   Port 0              01/01/70 00:00
      Hhm, still no answer??              01/01/70 00:00
         This doc explained everything              01/01/70 00:00
            it should be the first reference!              01/01/70 00:00
      P0.1              01/01/70 00:00
         start a new thread              01/01/70 00:00
         yes to both - it\'s \"bible time\"              01/01/70 00:00

Back to Subject List

Topic	Author	Date
about port 0 0f 8051mc		01/01/70 00:00
already answered		01/01/70 00:00
P0 pullups		01/01/70 00:00
Tristate (pedant mode)		01/01/70 00:00
This thread turns to helter-skelter		01/01/70 00:00
I never heard of that		01/01/70 00:00
*I never heard of that ?*		01/01/70 00:00
I never heard of that ?		01/01/70 00:00
Tristate (pedant mode, again)		01/01/70 00:00
three states		01/01/70 00:00
not at all confusing		01/01/70 00:00
confusing open drain/collector with tristate ...		01/01/70 00:00
Not quite true		01/01/70 00:00
much 'can' be done		01/01/70 00:00
read the datasheet ... it is "open-drain"		01/01/70 00:00
advantage		01/01/70 00:00
that it is not clogged		01/01/70 00:00
or a wire-or-ed output		01/01/70 00:00
????		01/01/70 00:00
How would you realize an input /output topology?		01/01/70 00:00
why		01/01/70 00:00
this is the diagram of the "inside" of chip		01/01/70 00:00
please comment		01/01/70 00:00
1) Maybe, 2) False, 3) False		01/01/70 00:00
FAQ		01/01/70 00:00
Have you read at all what I wrote??		01/01/70 00:00
Port 0		01/01/70 00:00
Hhm, still no answer??		01/01/70 00:00
This doc explained everything		01/01/70 00:00
it should be the first reference!		01/01/70 00:00
P0.1		01/01/70 00:00
start a new thread		01/01/70 00:00
yes to both - it\'s \"bible time\"		01/01/70 00:00