EMSCC™ Enhanced Mono Serial Communication Controller Z85233 Product Brief PB005802-0608 FEATURES • Hardware and software compatible with Zilog's SCC/ ESCC™ • Deeper Data FIFOs – 4-Byte Transmit FIFO – 8-Byte Receive FIFO • Programmable FIFO Interrupt Levels Provide Flexible Interrupt Response • Many Improvements toSupport SDLC/ HDLCTransfers: – Deactivation of /RTS Pin after Closing Flag – Automatic Transmission of the Opening Flag – Automatic Reset of Tx Underrun/EOM Latch – Complete CRC Reception – TxD pin Automatically Forced High with NRZI Encoding when Using Mark Idle. – Receive FIFO Automatically Unlocked for Special Receive Interrupts when Using the SDLC Status FIFO. – Back-to-Back Frame Transmission Simplified • Easier Interface to Popular CPUs • Fast Speeds: – 10.0 MHz for Data Rates up to 2.5 Mbit/ Sec. – 16.384 MHz for Data Rates up to 4.096 Mbit/Sec. -20.0 MHz for Data Rates up to 5.0 Mbit/Sec. • Improved SDLC Frame Status FIFO • Low Power CMOS • New Programmable Features Added with Write Register 7' • Write registers: WR3, WR4, WR5, and WR10 are Now Readable • Read Register 0 Latched During Access • Software Interrupt Acknowledge Mode • DPLL Counter Output Available as Jitter-Free Clock Source • /DTR//REQ Pin Deactivation Time Reduced • A Full-Duplex Channel with a Crystal Oscillator, Baud Rate Generator, and Digital PhaseLocked Loop. • Multi-Protocol Operation Under Program Control • Asynchronous Mode/Synchronous Mode GENERAL DESCRIPTION The Zilog Enhanced Mono Serial CommunicationController, Z85233 EMSCC, is a software compatible CMOS member of the SCC family introduced by Zilog in 1981. The EMSCC is a full-duplex data communications controller capable of supporting a wide range of popular protocols. The Z85233 EMSCC is a single channel version (Channel A) of Zilog's Z85230 ESCC. Based on Zilog's unique Superintegration™ Technology, the EMSCC is compatible with designs using Zilog's SCC and ESCC to receive and transmit data. It has many improvements that significantly reduce CPU overhead. The addition of a 4-byte transmit FIFO and an 8-byte receive FIFO significantly reduces the overhead required to provide data to, and get datafrom, the transmitter and receiver. The EMSCC also has many features that improve packet handling in SDLC mode. The EMSCC will Copyright ©2008 by Zilog®, Inc. All rights reserved. www.zilog.com Z85233 EMSCC™ Enhanced Mono Serial Communication Controller automatically: transmit a flag before the data, reset the Tx Underrun/EOM latch, force the TxD pin high at the appropriate time when using NRZI encoding, deassert the /RTS pin after the closing flag, and better handle ABORTed frames when using the 10x19 status FIFO. The combination of these features along with the deeper data FIFOs significantly simplifies SDLC driver software. The CPU hardware interface has been simplified by relieving the databus setup time requirement and supporting the software generation of the interrupt acknowledge signal (/INTACK). These changes allow an interface with less external logic to many microprocessor families while maintaining compatibility with existing designs. I/O handling of the EMSCC is improved over the SCC with faster response of the /INT and /DTR//REQ pins. Databus Control The many enhancements added to the EMSCC permits a system design that increases overall system performance with better data handling and less interface logic. Note: All Signals with a preceding front slash, "/", are active Low, e.g.: B//W (WORD is active Low); /B/W (BYTE is active Low, only). Power connections follow conventional descriptions below: Connection Circuit Device Power VCC VDD Ground GND VSS Internal Control Logic Channel A Register Interrupt Control Logic Channel B Register C hannel A CPU & DMA Bus Interface /INT Interrupt /INTACK IEI Control IEO C hannel B Figure 1. Z85233 Functional Block Diagram PB005802-0608 Page 2 of 4 Z85233 EMSCC™ Enhanced Mono Serial Communication Controller T rans mit Logic Transmit MUX Transmit Buffer T xDA Data Encoding & CRC Generation Receive and Transmit Clock Multipexer /T R xC A /R T xC A Digital Phase-Locked Loop Crystal Oscillator Amplifier Baud Rate Generator Modem/C ontrol Logic R eceive Logic Rec. Status Rec. Data Receive MUX FIFO 3 Byte FIFO 3 Byte SDLC Frame Status FIFO 10 x 19 /C T S A /DC DA /S Y NC A /R T S A /DT R A//R E QA R xDA CRC Checker, Data Decode & Sync Character Detection Figure 2. Channel A Exploded View PB005802-0608 Page 3 of 4 Z85233 EMSCC™ Enhanced Mono Serial Communication Controller Warning: DO NOT USE IN LIFE SUPPORT LIFE SUPPORT POLICY ZILOG'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF ZILOG CORPORATION. As used herein Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. Document Disclaimer ©2008 by Zilog, Inc. All rights reserved. Information in this publication concerning the devices, applications, or technology described is intended to suggest possible uses and may be superseded. ZILOG, INC. DOES NOT ASSUME LIABILITY FOR OR PROVIDE A REPRESENTATION OF ACCURACY OF THE INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED IN THIS DOCUMENT. Z I L O G A L S O D O E S N O T A S S U M E L I A B I L I T Y F O R I N T E L L E C T U A L P R O P E RT Y INFRINGEMENT RELATED IN ANY MANNER TO USE OF INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED HEREIN OR OTHERWISE. The information contained within this document has been verified according to the general principles of electrical and mechanical engineering. Z8, Z8 Encore!, Z8 Encore! XP, Z8 Encore! MC, Crimzon, eZ80, and ZNEO are trademarks or registered trademarks of Zilog, Inc. All other product or service names are the property of their respective owners. PB005802-0608 Page 4 of 4