70
C141-C015
1.6.4 RESELECTION
phase
The SCSI device operated as a TARG selects an INIT in the RESELECTION phase. This phase
is an option for the system, and this phase can only be used in systems with the ARBITRATION
phase implemented.
When the TARG re-starts the command processing under the disconnection on the SCSI bus, the
TARG reconnects with the INIT using this phase.
(1) Start
sequence
A TARG performs the RESELECTION phase in the following sequence after obtaining control of
the SCSI bus through the ARBITRATION phase (see Figure 1.29).
(a) Parity Protection is disabled
1) TARG waits at least Bus Clear Delay + Bus Settle Delay after asserting the SEL signal in
the ARBITRATION phase.
2) The TARG asserts the I/O signal with sending the SCSI IDs of the TARG itself and INIT
to the SCSI bus (the SCSI device that gets the bus usage right by asserting the I/O signal
is recognized as a TARG).
3) The TARG releases the BSY signal after waiting at least Deskew Delay
×
2, and the
TARG shall then wait the response (BSY signal) from the INIT after at least Bus Settle
Delay passed.
(b) Parity Protection Enabled
1) The SCSI device that won arbitration has both the BSY and SEL signals asserted and has
delayed at least one Bus Clear Delay plus one Bus Settle Delay before ending the
ARBITRATION phase.
2) The SCSI device that won arbitration identifies itself as a TARG by asserting the I/O
signal.
3) The TARG also sets the DATA BUS to a value that is the logical OR of TARG's SCSI ID
bit, the INIT's SCSI ID bit and the appropriate parity bit(s).
4) The TARG waits at least two System Deskew Delays and releases the BSY signal.
5) The TARG then waits at least one Bus Settle Delay before attempting to detect an
assertion of the BSY signal by the INIT.
Summary of Contents for MBA3300 NP SERIES
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Page 69: ...C141 C015 63 Figure 1 26 ARBITRATION phase ...
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Page 117: ...1 37 C141 C007 Figure 1 43 Bus phase sequence 1 of 2 ...
Page 118: ...38 C141 C015 Figure 1 43 Bus phase sequence 2 of 2 ...
Page 128: ...48 C141 C015 Figure 1 47 SPI information unit sequence during initial connection ...
Page 129: ...1 49 C141 C007 Figure 1 48 SPI information unit sequence during data type transfers ...
Page 130: ...50 C141 C015 Figure 1 49 SPI information unit sequence during data stream type transfers ...
Page 131: ...1 51 C141 C007 Figure 1 50 SPI information unit sequence during status transfers ...
Page 155: ...1 75 C141 C007 Figure 1 56 Connection to the LVD receivers ...
Page 161: ...Figure 2 1 Message format 154 C141 C015 ...
Page 166: ...Figure 2 2 SCSI pointer configuration C141 C015 159 ...
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