Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
74
• ABCM - Alternate BB-Credit model
When set to one, this flag indicates that the Port supports the Alternate BB-Credit model. As per the FC-AL Specifi-
cation, an L_Port and must support the Alternate BB-Credit model. The drive checks the value returned by the
FL_Port and will revert to PLDA behavior if it is not set to one. The drive sets this field to 1b.
•DHD - Dynamic Half Duplex
When set to one, this flag indicates that the Port supports the Dynamic Half Duplex. The drive sets this field to 0b.
• PL - Payload Length
When set to one, this flag indicates that FLOGI Payload Length shall be 256 bytes. If set to zero, the flag specifies
that the normal 116 byte FLOGI payload specified in FC-PH-2. The drive sets this field to 0b.
The Buffer to Buffer Receive Data Field size indicates the largest frame payload (in bytes) that the Port can receive. Sizes
less than 128, greater than 2112, or not divisible by 4 are invalid. The drive check this field in the FLOGI_ACC payload and
will revert to PLDA behavior if an invalid value is returned. The drive sets this field to 2048.
The R_A_TOV field specifies the R_A_TOV (Resource Allocation Timeout Value) supplied by the fabric in units of 1ms. The
fabric port sets this field in its FLOGI_ACC payload. This field is reserved in the FLOGI_REQ and the drive therefore sets
this field to zero. After FLOGI is complete, the drive will use this value for R_A_TOV until the drive is reset, reverts to PLDA
behavior, or performs another FLOGI.
The E_D_TOV field specifies the E_D_TOV (Error Detect Timeout Value) supplied by the fabric in units of 1ns or 1ms. The
fabric port sets this field in its FLOGI_ACC payload. This field is reserved in the FLOGI_REQ and the drive therefore sets
this field to zero. After FLOGI is complete, the drive will use this value for E_D_TOV until the drive is reset, reverts to PLDA
behavior, or performs another FLOGI.