The Z80189/Z8L189 are cost-effective modem controllers that address a new generation of data pumps having the HDLC formatting feature. Data pumps of these types do not require an HDLC interface; therefore, the Z80189 does not need the ESCC TM. The addition of the PC DMA Mailbox Registers allow DMA data transfer between the PC memory and the modem speaker/microphone CODEC. The Z80189 is a smart peripheral controller chip for modem (in particular V.34 applications), fax, voice messaging, and other communications applications.