Method and structure for allocating sites in an expanded SCB array

摘要

A parallel SCSI host adapter uses an expanded SCB array for both non-Packetized and Packetized SCSI Protocols. The expanded SCB array is partitioned into a low page and a high page. SCBs for non-Packetized SCSI Protocol target devices that utilize a one-byte tag are stored in the low page and the storage site number is the tag. SCBs for Packetized SCSI Protocol target devices that utilize a multi-byte tag are stored on both the low page and the high page. For Packetized SCSI Protocol target devices, the two-bytes required to identify the page and the number of the storage site in the page are used as the tag. SCBs for Packetized SCSI Protocol target devices are stored in the low page only if there are no available storage sites in the high page.