Microprocessor controller and interface unit - provides direct memory access mode with protection against errors in transmission

摘要

A central control unit (CCU) that is microprocessor based (MP) is in communication with a number of line connected peripherals via the control units of the peripherals (PCV). Such a unit is configured for a subscriber or public network module (TE,AE). The central controller unit has the microprocessor coupled to an interface stage (PBC) via a direct memory access address circuit (DMA-L). An address bus (AD) allows multiplexed access by the microprocessor of the programme memory (P) and a data memory (RAM). The interface has a standard protocol (HDLC) controller for the exchange of data between individual units. ADVANTAGE - Avoids errors in data transmission without requiring external controller.