Have the internal pullups changed on the Net+50-3 die? Pin 200 appears to have a 20K internal pullup on the -1 and on the -3 it has dropped to 10K. I’m wondering what other internal pullups have changed value. Is this documented somewhere? Also, where can I find the Net+50-1 to Net+50-3 Migration document?
Please find enclosed the document that lists the differences between 50-1 and 50-3.
Thank you, muscleman. We are still wondering about the pull-up’s, though. The difference in pin 200 caused us a considerable amount of grief, because as a result, a CPLD on our board could not be programmed. Several days of investigation by two engineers were required to determine the cause, since there were many possibilities, all difficult to resolve. The solution was fortunately simple, involving a change in one resistor value. Are all the PDATA lines pulled up twice as strongly on the -3 as on the -1 part? What about other lines?
None of the NET+ARM versions have pull-up resistors. They do have current sources and one current sink on TRST_. This current source is from 130-352uA. Page 422 50-3 HRG. The 50-1 HRG has the same current range, but misleadingly calls it a pull-up. It is the same for both the 50-1 and the 50-3. In all cases whether you call it a pull-up or current source you would use 352uA as the current to overcome. VIL = .8V IR = E 2.7K pull-down .000352 x 2700 = .9504V (too high for VIL) 1K pull-down .000352 x 1000 = .352V (Produces solid VIL with noise margin) A 1K pull-down is required to produce a safe logic “0” to cover the worst case current source.