Micron’s modules are manufactured to be hardware-compatible with both parity and non-parity systems.
Par_in (parity in) and the high order address signals have a weak (100K-ohm) pull-down resistor to stabilize the inputs from oscillating around the switch point.
Err_out (parity error out) is an open drain and should be left as a true no connect unless used in a parity system.
The SPD data on a parity module does reflect parity. In rare occasions, the firmware or BIOS of a non-parity system will err on the parity bit in the SPD. For this reason, the system designer should ensure that the firmware of the non-parity system expects or ignores this portion of the SPD data.