How do you do to terminate the 7842 external DDR memory interface is it is not used.
UG-214, ADV7842 hardware guide, Appendix C list what to do with unsed pins
Can I use a common (single) pull down for the 15 data pins?
One pull down per bank of 8 DQ pins should be good. Just make sure you never turn on the memory controller with your scripts during initializations.
Is a 4.7K still a good value (per bank)?
Should be good
This just came out for the ADV7850 and applies to ADV7842
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