HD64570 Datasheet, PDF (5/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

Preface
The HD64570 serial communications adaptor (SCA) peripheral chip enables a host
microprocessor to perform asynchronous, byte-synchronous, or bit-synchronous serial
communication. Its two full-duplex, multiprotocol serial channels support a wide variety of
protocols, including frame relay, LAPB, LAPD, bisync, and ™DDCMP. Its built-in direct
memory access controller (DMAC) is equipped with a 32-stage FIFO and can execute chained-
block transfers. Due to its DMAC and 16-bit bus interface, the SCA supports serial data transfer
rates up to 12 Mbits/s without monopolizing the bus, even in full-duplex communication. Other
on-chip features of the SCA, including four types of MPU interfaces, a bus arbiter, timers, and an
interrupt controller, provide added functionality in a wide range of applications, such as frame
relay exchanges/system multiplexes, private branch exchanges, computer networks, workstations,
ISDN terminals, and facsimile.
™DDCMP is a trademark of Digital Equipment Corporation.
Rev. 0, 07/98, page i of 11