IOMux Tool - Why do some single-function pad/signals show up without a checkbox?

[ChrisWilliamson]

From Customer:

“I understand that there are certain signals and pads that don't have muxing options, in other words those are dedicated signals and pads. By default the tool has already allocated (filled in) in both the Signals Tab and the Ball Diagram Tab, the JTAG (sjc group) and Memory (mmdc group) pins, but it will not allow you to at least select other dedicated groups such as the PCIe group.

Can you explain why the tool does this or if there is a way to select the groups so that they "show up" as used in the Tabs”

[ChrisWilliamson · Accepted solution]

The JTAG and MMDC groups are single function pads, but they are shown as checked and grayed out because they do have pad control registers that the user could use to adjust the electrical characteristics of the pads, and code is required to initialize those pads.

The other single function pads/signals are shown without a checkbox because they have no IOMUXC registers associated with them and therefore no code needs to be generated to configure them. They are simply included for completeness so all signals for a module are represented even if they do not need IOMUXC configuration.

Hope that helps. Please feel free to ask any questions or report problems.

Best regards,

Chris