I’m designing a board that will use an AT91SAM7XC512, this chip has a JTAGSEL pin that the datasheet says it’s to activate “JTAG Boundary Scan”, which apparently is supposed to allow test equipment to read the I/O pin status with JTAG testing equipment.
The datasheet says it has an internal pull-down to ground, I can optionally connect a external pull-down resistor (suggested 1 kohm), or connect it directly to ground. Bringing it high will activate JTAG boundary scan.
On the Netduino schematics, this JTAGSEL pin is connected directly to ground. Note that Netduino does not have a JTAG connector at all.
On the Olimex SAM7-H series boards, JTAGSEL are connected to a jumper to 3.3V. On the Olimex SAM7-P series boards, the JTAGSEL pin is completely unconnected. Both of the Olimex boards feature a JTAG port.
My own design will have a JTAG port, but I don’t have enough room for anything to be connected to JTAGSEL. I want to make sure that JTAGSEL can be left unconnected and I would still be able to utilize the JTAG port for programming and debugging. Can I simply leave JTAGSEL unconnected?