What is a linkage bit in a BSDL?
The linkage bit in a Boundary Scan Description Language (BSDL) is use to describe a nondigital pins such as power, ground, no-connects, or analog signals in a boundary scan device.
entity example is
generic (PHYSICAL_PIN_MAP : string := "DW_PACKAGE");
port (CLK:in bit; Q:out bit_vector(1 to 8);
D:in bit_vector(1 to 8);
GND, VCC:linkage bit;
TMS, TDI, TCK:in bit);