JTAG offers fundamentally two operations: scan bits through the instruction register or scan bits through a data register. The only other operation required is the ability to reset the TAP controller.

The SystemC interface reflects this, with classes representing a TAP instruction register scan (TapActionScanIR), a TAP data register scan (TapActionScanDR) and reset (TapActionReset).

The interface provides a SystemC module class representing the JTAG interface, JtagSC. The user can queue IR scan, DR scan and reset operations and JtagSC will generate the correct sequence of TAP pin outputs.