User’s Guide 21020285 D
Appendix E Design Differences
Features no longer Supported Page E - 3
To make differences easy to find, the following descriptions include page
numbers that reference other parts of this User’s Guide.
Features no longer SupportedThe following design features are not supported in the RF3880:
Scatter/Gather Operations
The RF3880 does not support the Scatter/Gather feature that was available in
previous adapters. If your driver used the Scatter/Gather feature, you must now
issue individual SCSI commands for each descriptor pair in the Scatter/Gather
Descriptor Block.
Byte and Word Swapping of Data
The RF3880 does not support word swapping and byte swapping of data. Thus,
Bits 3 and 4 of the Control Field of the Address Buf fer P ort must be zer o. This
is shown in Table 6 on page 2 - 8. Any required data swapping must now be
done by the driver/system. Note that the RF3880 still supports swapping of
Control Structures.
Odd Byte Handling
The RF3880 does not support a selectable Odd Byte Handling algorithm. In
previous designs, Odd Byte Handling was selected in the General Options
Command, Bit 3 of the Select Flags field. As shown in Table 73 on page 7 -
16, Bit 3 of this field is now ignored.
Previously, the Odd Byte Handling algorithm currently selecte d wa s reported
in the Board Information Command, Bit 3 of the Select Flags Fie ld. As shown
in Table 92 on page 7 - 34, Bit 3 is now returned as a zero.