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Altera_Forum
Honored Contributor
17 years agoDFF Clock Polarity & Other signal polarities
Hi all,
I'm relatively new to Quartus, but have used Altera and their other tools long ago. Currently, I'm using Quartus II web edition using Block/Schematic entry building a MAX II device. A question that always comes up is: What is the active-edge/polarity of the various parts of the LEs ? Namely, the flip-flop clocks. Also, what's the polarity of the tri-state control on the IOEs ? I guess a broader question would be, where does one find this low-level info on the specifics of the LEs ? A 2nd Question: When specifying, for example, a device-wide output enable in the Device and Pin Options, where/how is the pin assigned? Thanks for your help RW4 Replies
- Altera_Forum
Honored Contributor
Thanks Pletz, that's what I was looking for.
- Altera_Forum
Honored Contributor
--- Quote Start --- Thanks pletz, The document you linked is, I believe, a sub-section of the handbook ... which I downloaded and read a few days ago. More specifically to my question, refer to the IO structure diagram on page 2-24 of the document you linked. As one can see, there's a great deal of configuration that can be specified for an IO point. Where I'm a bit confused is how these various settings are configured using schematic symbols. For example, if you want to specify an open drain output, I believe you place a Primitives/Buffer/opndrn symbol before the pin. There are, however, many more options that I'm having trouble finding (or guessing) in the symbols library. What I need is a cross-reference that correlates the desired I/O function to the relative symbol in the library. Does such a cross-reference exist ? --- Quote End --- Hi RWey, the real I/O specification is not done in the schematic ( as far as I know). I/O standards, driver strength like other I/O features are logic option, which could be set in the assignment editor. Kind regards GPK - Altera_Forum
Honored Contributor
Thanks pletz,
The document you linked is, I believe, a sub-section of the handbook ... which I downloaded and read a few days ago. More specifically to my question, refer to the IO structure diagram on page 2-24 of the document you linked. As one can see, there's a great deal of configuration that can be specified for an IO point. Where I'm a bit confused is how these various settings are configured using schematic symbols. For example, if you want to specify an open drain output, I believe you place a Primitives/Buffer/opndrn symbol before the pin. There are, however, many more options that I'm having trouble finding (or guessing) in the symbols library. What I need is a cross-reference that correlates the desired I/O function to the relative symbol in the library. Does such a cross-reference exist ? - Altera_Forum
Honored Contributor
--- Quote Start --- Hi all, I'm relatively new to Quartus, but have used Altera and their other tools long ago. Currently, I'm using Quartus II web edition using Block/Schematic entry building a MAX II device. A question that always comes up is: What is the active-edge/polarity of the various parts of the LEs ? Namely, the flip-flop clocks. Also, what's the polarity of the tri-state control on the IOEs ? I guess a broader question would be, where does one find this low-level info on the specifics of the LEs ? A 2nd Question: When specifying, for example, a device-wide output enable in the Device and Pin Options, where/how is the pin assigned? Thanks for your help RW --- Quote End --- Hi, for detailed info's look into: http://www.altera.com/literature/hb/max2/max2_mii51002.pdf Kind regards GPK