Write Example 3 –

Burst = 16 Dwords, Cache Line Size = 8 Dwords:

A to B: MW (6 bytes)

A to C: MW (13 bytes)

A to D: MW (17 bytes)

C to D: MW (5 bytes)

C to E: MW (21 bytes)

D to F: MW (32 bytes)

A to H: MW (15 bytes)

MWI (64 bytes)

MW (2 bytes)

A to G: MW (15 bytes)

MWI (32 bytes)

MW (18 bytes)

2.1.3.6 Memory-to-Memory Moves

Memory-to-Memory Moves also support PCI cache commands, as described above, with one limitation. Memory Write and Invalidate on Memory-to-Memory Move writes are only supported if the source and destination address are quad word aligned. If the source and destination are not quad word aligned (that is, Source address [2:0] == Destination Address [2:0]), write aligning is not performed and Memory Write and Invalidate commands are not issued. The LSI53C875A is little endian only.

2.2 SCSI Functional Description

The LSI53C875A provides an Ultra SCSI controller that supports an

8-bit or 16-bit bus. The controller supports Wide Ultra SCSI synchronous transfer rates up to 40 Mbytes/s. The SCSI core can be programmed with SCSI SCRIPTS, making it easy to “fine tune” the system for specific mass storage devices or Ultra SCSI requirements.

The LSI53C875A offers low level register access or a high-level control interface. Like first generation SCSI devices, the LSI53C875A is

2-16

Functional Description

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LSI 53C875A technical manual Scsi Functional Description, Memory-to-Memory Moves