public BigInteger readRegister(String regName) {
		Register reg = getRegister(regName);
		if (reg == null) {
			throw new IllegalArgumentException("Undefined register: " + regName);
		}
		return readRegister(reg);
	}
@return the low-level emulator execution state
Ghidra/Framework/Emulation/src/main/java/ghidra/app/emulator/EmulatorHelper.java