Ease of Use

Flexibility

Reliability

Testability

1.4.1SCSI Performance

To improve SCSI performance, the LSI53C875A:

Has integrated SE transceivers.

Bursts up to 512 bytes across the PCI bus through its 944 byte FIFO.

Performs wide, Ultra SCSI synchronous transfers as fast as 40 Mbytes/s.

Can handle phase mismatches in SCRIPTS without interrupting the system processor, eliminating the need for CPU intervention during an I/O disconnect/reselect sequence.

Achieve Ultra SCSI transfer rates with an input frequency of 20 MHz with the on-chip SCSI clock quadrupler.

Includes 4 Kbytes internal RAM for SCRIPTS instruction storage.

Has 31 levels of SCSI synchronous offset.

Supports variable block size and scatter/gather data transfers.

Performs sustained memory-to-memory DMA transfers to approximately 100 Mbytes/s.

Minimizes SCSI I/O start latency.

Performs complex bus sequences without interrupts, including restoring data pointers.

Reduces ISR overhead through a unique interrupt status reporting method.

Uses Load/Store SCRIPTS instructions which increase performance of data transfers to and from the chip registers without using PCI cycles.

Has SCRIPTS support for 64-bit addressing.

Supports multithreaded I/O algorithms in SCSI SCRIPTS with fast I/O context switching.

LSI53C875A Benefits Summary

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LSI 53C875A technical manual Scsi Performance