Specifications

If DT_REQ is set to one and IU_REQ is set to zero, the following values are used.
Asynch(Asynch Mode)Mt = 19h26 <= Mi <= 255
Fast-10100Mt = 19h13 <= Mi <= 25
Fast-2050Mt = 0Ch11 <= Mi <= 12
Fast-4025Mt = 0Ah10 <= Mi <= 10
Fast-8012.5Mt = 09h0<=Mi<= 9
Transfer Rate
Target Transfer
Period (ns)
Target
Response
Initiator Request
Figure 188. Initiator Request/Target Response (DT_REQ = 1, IU_REQ = 0
If both DT_REQ and IU_REQ are set to zero, the following values are used.
Asynch(Asynch Mode)Mt = 32h51 <= Mi <= 255
Fast-5200Mt = 32h26 <= Mi <= 50
Fast-10100Mt = 19h13 <= Mi <= 25
Fast-2050Mt = 0Ch11 <= Mi <= 12
Fast-4025Mt = 0Ah0<=Mi<= 10
Transfer Rate
Target Transfer
Period (ns)
Target
Response
Initiator Request
Figure 189. Initiator Request/Target Response (DT_REQ = 0, IU_REQ = 0
! REQ/ACK Offset determines the maximum number of REQs allowed to be outstanding before a
corresponding ACK is received at the drive during synchronous or paced transfers. The REQ/ACK
Offset value is chosen to prevent overflow conditions in the reception buffer and offset counter of the
drive. The drive supports maximum offset of 127 (7Fh). A REQ/ACK Offset value of zero indicates
asynchronous data transfer mode and that the Transfer Period Factor and the protocol options bits
except QAS_REQ will be ignored.
! Transfer Wide Exponent defines the transfer width to be used during DATA IN and DATA OUT
phases. If any of the protocol options bits other than QAS_REQ are set to one, then only wide transfer
agreements are valid. The following values are supported.
– 00h: 8 bit data bus (Narrow transfer agreement).
– 01h: 16 bit data bus (Wide transfer agreement).
! PCOMP_EN (Precompensation Enable) is used to negotiate if the precompensation is enabled on all
signals transmitted during DT DATA phases. The drive supports PCOMP_EN.
! RTI (Retain Training Information) is used to negotiate if the saving of paced data transfer training in-
formation is made so that the retraining is not necessary on each connection. The drive support RTI.
! RD_STRM (Read Streaming and Read Flow Control Enable) is used to negotiate if read streaming
and read flow control are enabled. The drive supports RD_STRM.
! WR_FLOW (Write Flow Control Enable) is used to negotiate if write flow control is enabled during
write streaming. The drive supports WR_FLOW.
Ultrastar 146Z10 hard disk drive specifications
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