1F 1E 1D 1C 1B 1A 19 18 17 16 15 14 13 12 11 10 F E D C B A 9 8 7 6 5 4 3 2 1 0Data Pointer 1Data Length 1Data Pointer 2Data Length 2...Data Pointer nData Length nThe data lengths must be less than 4 MBytes and the total length of the transfermust be less than 16 MBytes.Data or Scatter/Gather List LengthThis 32-bit field contains the length in bytes (least significant byte first) of the datatransfer. The host should always store a value in this field (even if data transfer is tobe suppressed), if a data phase is expected during the SCSI command. Otherwise, adata overrun error will occur. If no data transfer is expected, this field should be setto 0. The data lengths must be less than 4 MBytes.If the Scatter/Gather flag (Flag Word 1, bit 12) is set to one, this field contains thelength in bytes of the Scatter/Gather list. This value must be nonzero and a multipleof eight (8), otherwise, a specification error will be reported by the host adapter. Thelength of the Scatter/Gather list is limited to 1 KByte.Status Block PointerThis 32-bit field contains the physical memory address (least significant byte first) ofthe status block. The status block is written to by the host adapter and used by thehost to determine the completion status of a control block operation.The length of the status block is always 32 bytes, though the number of bytes storedby the host adapter may be less.This field is required for all control blocks. However, the host adapter will bypasswriting to the status block if the control block completes without error and the Dis-able Status Block flag (Flag Word 1, bit 14) is set to one.EISA-to-Fast SCSI Host Adapter Enhanced Mode Firmware Description6-11
