Data exchange interface that directly transmits control signals either to a microprocessor or a D.M.A. controller via a first and second control line respectively

摘要

A communication system includes a data exchange interface which is coupled via an internal bus to a microprocessor and a DMA unit. For controlling the data exchange, the interface transmits control signals either to a microprocessor or a DMA unit. The control signals are acknowledged each time. For realizing an efficient data exchange via the interface, the interface is an I2C bus interface with minimum load of the microprocessor, and transmits a first group of control signals by a first control line to the DMA unit and a second group of control signals by a second control line to the microprocessor. By respective settings of the interface, a selectable part of the control circuitry may be transferred from the microprocessor to the DMA unit. The total number and type of control signals (interrupts) which correspond each to a specific mode of the interface may be retained.