HD64570 Datasheet, PDF (117/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

Section 5 Multiprotocol Serial Communication Interface
(MSCI)
5.1 Overview
The multiprotocol serial communication interface (MSCI) supports three different communication
modes: asynchronous, byte synchronous, and bit synchronous.
The two full-duplex channels of the MSCIs, built in the SCA, have identical functions but operate
independently.
5.1.1 Functions
The MSCI features the following functions:
• Program-selectable operating modes: Asynchronous, byte synchronous, and bit synchronous
• Transmission codes NRZ, NRZI, Manchester, FM0, and FM1 supported (only NRZ code
supported in asynchronous mode)
• Full-duplex communications, auto echo, and local loop-back functions available
• 32-stage transmit and receive buffers provided
• Modem control signals RTS, CTS, and DCD automatically controlled using the auto-enable
function
 RTS (request to send): General-purpose output/transmit request
 CTS (clear to send): General-purpose input/transmit enable/transition-triggered interrupt
 DCD (data carrier detect): General-purpose input/receive carrier detection/transition-
triggered interrupt
• Programmable on-chip baud rate generator for transmission and reception
• Selectable clock sources: External clock input, on-chip baud rate generator output, and
internal ADPLL (advanced digital PLL) output
• Noise suppression function for receive clock and receive data
• Data transmission rate of 50 bps to 7.1 Mbps for a 10-MHz system clock, and 50 bps to 12
Mbps for a 16.7-MHz system clock
• Four interrupt signals: RXRDY, TXRDY, RXINT, and TXINT
Functions of the MSCI in asynchronous, byte synchronous, and bit synchronous operating modes
can be summarized as follows:
• Asynchronous Mode
 Programmable character length (5-8 bits/character) for transmission and reception
 Programmable stop bit length (1, 1.5, or 2 bits)
Rev. 0, 07/98, page 101 of 453