It supports synchronous communications with one or two SYNC characters, with internal or external SYNC detection. Both the transmit and receive data paths are double buffered. It has four modem control lines. The M8251A is fully programmable by an 8-bit CPU interface. The operating mode of the M8251A is programmed by writing to the mode control registers, and SYNC registers, using the 8-bit CPU interface.
Transmission can then begin by writing to the transmit buffer.
In synchronous mode character reception will not begin until the SYNC character, or characters, are detected. When each character has been received it is transferred to the receive buffer to be read by the CPU interface. A per-use fee is associated with this megacell. Contact AMIS Marketing for more information. All rights reserved.