according to the AT32UC3B datasheet (page 617/618), revision A, B and C of the AT32UC3B were/ are produced.
How can I know, which revision of the CPU is on my board?
No the datasheet says that there is 2 UC3B revision:
- revision B: this is the current i have on my EVK1101, the part is labeled "-ES".
- revision E: this part will be sampled in Jan 08 (not labeled with "-ES").
I guess the way to know which part you have is to look at it see if you have -ES written (i have -UES that 's the same) or not. Or you could read the JTAGID.
Yes, you are right, there is revision B and E mentioned in the datasheet.
My chip is marked with -UES, so I have Rev B. In the Errata it is said:
Local bus is only available for silicon RevC and later.
Does anybody know, what the local bus is good for?
Seems quite nice to access the GPIO register at CPU speed (1cycle CPU = 1 access to GPIO reg through local bus), with the pad speed limitation of course.
CPU access to GPIO register through HSB and PBA bridge (that's the only possible way on revB) takes more cycles.
It's good when you have IO bit-banging protocol.
Thank you. I was reading the datasheet again,
and found much info about the local bus.
What does "pad speed limitation" mean?
I mean the maximum speed that the pad accepts having a good "square" waveform (note the "good" here depends on the pad load capacitance).
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