Function Codes - IBM DDRS-39130 - Ultrastar 9.1 GB Hard Drive Specifications

11.3 Function codes

The following function codes are supported.
Function Code
00000b Isolate
00001b Isolate and set priority flag
00011b Configuration process complete
01111b Dominant initiator contention
11111b Synchronization
others reserved
Figure 138. SCAM Identification string
Isolate This function code may be used by SCAM initiators to assign ID's to SCAM device. After the
function code, SCAM targets with unassigned ID's participate in an isolation stage. This stage normally
terminates with a single SCAM target isolated.
Isolate and set priority flag This function code operates exactly as the Isolate function described above
except that the only valid action codes are those that assign an ID to the isoleted device(s). This function
also causes the device's priority flag to be set to one.
Configuration process complete This function code is issued by the dominant SCAM initiator when the
bus configuration is complete and no further ID's are to be assigned. The drive with an unassigned ID
that observes this function code shall not respond to selection until a reset condition, power on or the
assignment od an ID during a subsequent SCAM protocol invocation.
Dominant initiator contention This function code selects one SCAM initiator, called the dominant
SCAM initiator, from possibly multiple SCAM initiators. When this function code is detected, the drive
shall do nothing but keep monitoring the bus until next valid function code is detected.
Syncronization This function code is issued to begin a new function sequence. When this function code
is detected, SCAM target shall begin a new function sequence regardless of whether the previous func-
tion sequence has been completed.
202
O E M Spec. of DDRS-3xxxx
Description