The 73K324L is a highly integrated single-chip modem IC which provides the functions needed to design a Quad-mode CCITT and Bell 212A compatible modem capable of operation over dial-up lines. The 73K324L adds V.23 capability to the CCITT modes of TDK Semiconductor Corporation's 73K224 one-chip modem, allowing a one-chip implementation in designs intended for European markets which require this added Modulation mode. The 73K324L offers excellent performance and a high level of functional integration in a single IC. The device supports V.22bis, V.22, Bell 212A, V.21, and V.23 operating modes, allowing both synchronous and asynchronous operation as defined by the appropriate standard.