Z8L189

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™. 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.

The Z80189/Z8L189 consists of an enhanced Z8S180 microprocessor, a 16550 MIMIC with increased MIMIC drive capability for direct connection to the IBM PC, XT, AT bus, and 24 bits of parallel I/O. Current PC modem software compatibility can be maintained with the Z80189's ability to mimic the 16550 UART chip. The Z80180 core is the intelligent controller between the data pump and 16550 MIMIC interface when used in internal applications. This intelligent controller performs the data compression and error correction on outgoing and incoming data.

The integration of COM Port Decode circuitry to the Z80189 allows the MIMIC to be selected for a specific COM Port Address (PC COM Port Address 1-4). COM Port Decode circuitry is simplified by allowing the user to select the MIMIC COM Port addresses through software, in addition to eliminating the need for external circuitry required for COM Port Decode logic.

The PC DMA and I/O Mailbox Interface can be used to provide communication paths between the PC Host and the Z80189. These new communication paths can be used for voice, DTAD, or jumperless COM Port selection.