Forum Discussion
Altera_Forum
Honored Contributor
Honored ContributorMax V JTAG Daisy Chain
I'm implementing a JTAG Daisy Chain for the first time on a PCB. Previously, on a prototype board I had two headers for JTAG programming but I'd like to utilize a daisy-chain configuration to reduce ...
Altera_ForumHonored Contributor
Honored Contributor --- Quote Start --- Makes perfect sense now. I can even see where to put the resistors in terms of layout: near the buffer. I'll go with 100 Ohms for this, as your schematic suggests. --- Quote End --- The value will be somewhere around 30-ohms. I generally put whatever is the closest part in the BOM for a board. Its not really important to get it right on the first revision of the board. You'll measure it, try a few different values, and settle on the one that looks good. --- Quote Start --- It might also be a good idea to put this on the SPI daisy chain. --- Quote End --- Its always a good idea to have point-to-point transmission lines when you can. --- Quote Start --- What book would you recommend for understanding transmission line effects on a PCB? --- Quote End --- I liked the book by Johnson&Graham, "High Speed Digital Design: A Handbook of Black Magic", 1993. Cheers, Dave
