Spi Data Stream Information Unit - Fujitsu MBA3073 SERIES Technical Manual

b) may change the C/D, I/O, or MSG signals on a SPI data stream information unit
boundary.
If during the last SPI data stream information unit, of a read stream, the P_CRCA signal was not
asserted and an INIT detects a REQ transition after receiving the last iuCRC for a SPI data stream
information unit that INIT shall receive the next SPI data stream information unit. If during the
last SPI data stream information unit the P_CRCA signal was asserted and an INIT detects a REQ
transition after receiving the last iuCRC for a SPI data stream information unit that INIT shall
logically disconnect from the current I_T_L_Q nexus.
If during a sequence of SPI data stream information units an INIT detects any change to the C/D,
I/O, or MSG signals after transmitting or receiving the last iuCRC for a SPI data stream
information unit that INIT shall consider the current I/O process to be logically disconnected or in
the case of detecting a BUS FREE phase or a MESSAGE IN phase to be physically disconnected.
The detection of a BUS FREE phase following a SPI data stream information unit by an INIT
shall be equivalent to the INIT receiving a DISCONNECT message.
The detection of a QAS REQUEST message following a SPI data stream information unit by an
INIT shall be equivalent to the INIT receiving a DISCONNECT message.
To end a sequence of SPI data stream information units an INIT may request a disconnect by
establishing an attention condition. The INIT shall continue to transfer or receive data, pad bytes
(if any), and iuCRC(s) until the TARG changes to the MESSAGE OUT phase.
During a sequence of SPI data stream information units the offset count is not required to go to
zero at the boundary of any SPI data stream information unit if the next SPI information unit is a

SPI data stream information unit.

Bit
7
Byte
0
n
(MSB)
2
3
4
11
The DATA field may contain any type of information (e.g., parameter lists, mode pages, user
data).
If the IUCRC INTERVAL field of the SPI L_Q information unit contains a value greater than
zero and less than the data length then there is an IUCRC field at each iuCRC interval in addition
to the iuCRC shown in table 1.29. These additional IUCRC fields are not shown in table 1.29.
1-59
Table 1.29 SPI data stream information unit
6 5 4 3 2
DATA
IUCRC
1 0
(LSB)
C141-C007