protected void deleteRegisterValueAtFunction(ListingActionContext context) {
		RegisterFieldLocation location = (RegisterFieldLocation) context.getLocation();
		Register register = location.getRegister();
		Address addr = location.getAddress();
		Command<Program> cmd = new SetRegisterCmd(register, addr, addr, null);
		if (!tool.execute(cmd, context.getProgram())) {
			Msg.showError(this, tool.getToolFrame(), "Register Context Error", cmd.getStatusMsg());
		}
	}
Shows the registers available in a program along with any values that are set.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/register/RegisterPlugin.java