Intel NETWORK PROCESSOR IXP2800 - Manual (Page 55)

Hardware Reference Manual 55
Intel
®
IXP2800 Network Processor
Technical Description
Verification is required to test only the order rules shown in Table 12 and Table 13 ).
Note: A blank entry in Table 12 means that no order is enforced.
Table 13 shows the architectural guarantees of order to access to the SAME SRAM Q_array entry
between a reference of any given type (shown in the column labels) and a subsequent reference of
any given type (shown in the row labels). The definition of first and second is defined by the order
they are received by the SRAM controller. The same caveats apply as for Table 12 .
Table 12. Address Reference Order
1 st ref
2 nd ref Memory
Read
CSR Read
Memory
Write
CSR Write
Memory
RMW
Queue /
Ring /
Q_Descr
Commands
Memory Read Order
CSR Read Order
Memory Write Order
CSR Write Order
Memory RMW Order
Queue / Ring / Q_
Descr Commands See
Table 13 .
Table 13. Q_array Entry Reference Order
1 st ref
2 nd ref
Read_Q
_Descr
head,
tail
Read_
Q_Des
cr
other
Write_Q
_Descr
Enqueue Dequeue Put Get Journal
Read_Q_Descr
head,tail
Order
Read_Q_
Descr other
Order
Write_Q_
Descr
Enqueue Order Order Order
Dequeue Order Order Order
Put Order
Get Order
Journal Order