1-2 General Description
Software development tools are availableto developers who use the
SCSI SCRIPTS language to create customized SCSI software
applications. The LSI53C810A allows easy firmware upgrades and is
supported by advanced SCRIPTS commands.
1.1 TolerANT®Technology
The LSI53C810A features TolerANTtechnology, which includes active
negation on the SCSI drivers and input signal filtering on the SCSI
receivers. Active negation actively drives the SCSI Request,
Acknowledge, Data, and Parity signals HIGH rather than allowing them
to be passively pulled up by terminators. Active negation is enabled by
setting bit 7 in the SCSI TestThree (STEST3) register.
TolerANTreceiver technology improves data integrity in unreliable
cabling environments where other devices would be subject to data
corruption. TolerANT receiversfilter the SCSI bus signals to eliminate
unwanted transitions, without the long signal delay associated with
RC-type input filters. This improveddr iverand receiver technology helps
eliminate double clocking of data, the single biggest reliability issue with
SCSI operations. The TolerANTinput signal filtering is a built in feature
of all LSI Logic fast SCSI devices. On the LSI53C8XX family products,
the user mayselect a filter ing period of 30 or 60 ns, with bit 1 in the SCSI
TestTwo (STEST2) register.
The benefits of TolerANTtechnology include increased immunity to noise
when the signal is going HIGH, better performance due to balanced duty
cycles,and improved fast SCSI transfer rates. In addition, TolerANTSCSI
devices do not cause glitches on the SCSI bus at power-up or
power-down, so other devices on the bus are also protected from data
corruption. TolerANT technology is compatiblewith both the Alter native
One and Alternative Twotermination schemes proposed by the American
National Standards Institute.