motorola 68HC99 Product Preview Oct85 free download

File name 68HC99_Product_Preview_Oct85.pdf

MOTOROLA _ SEMICONDUCTOR TECHNICAL DATA MC68HC99 Product Preview Hard Disk Controller (HOC) FN SUFFIX QUAD PACKAGE The MC68HC99 hard disk controller (HOC) provides an economical solution to the problem of controlling one or more 3.5 or 5.25 inch hard-disk units. In a single package the HOC contains a host interface, disk interface, rotating data buffers, and error detection and correction circuitry. The host interface is the proposed ANSI X3T9.3 small computer system interface (SCSI) which is compatible with the Shugart Associates system interface (SASI). It supports single or multi-host SCSI systems and bus disconnection and reconnection. Disk interfaces supported are: ST506, 412HP, ESDI step mode, and ESDI serial mode. Two on- chip data buffers provide fast data throughput without the need for sector interleaving. The error detection and correction circuitry is based on Reed- Solomon codes and all detection and correction is done without host system interaction. The HOC also has 12K bytes of mask-programmable ROM which is available for user developed firmware.