IBM3229P2035
Advance
IBM Packet Routing Switch Serial Interface Converter
Table 8: Packet Qualifier for Egress Data Packet
Data Packet
Bit 31
Bit 30
Bit 29
Bit 28
Bit 27
Bit 26
0
Bit 25
0
Bit 24
0
Shared
Memory
Status
Hold = ‘0’
Grant = ‘1’
Shared Memory Grant Pri-
ority Level
Output Queue Grant Pri-
ority Indicator
Bit Meaning
Memory Grant
Priority Level
Definition
Highest
Medium High
Medium Low
Lowest
0
0
1
1
0
1
0
1
Output Queue Grant
Priority Indicator
Highest
Medium High
Medium Low
Lowest
0
0
1
1
0
1
0
1
Data Packet
Priority Bit
Highest
Medium High
Medium Low
Lowest
0
0
1
1
0
1
0
1
3.3.4.1 Building the Egress Packet Qualifier Byte
• Shared Memory Information
- The bit PQ(2) is replaced by the shared memory information (SM) whose priority level corresponds to
shared memory grant priority levels PQ(0) and PQ(1) that cycle one priority after another.
• Output Queue Grant Priority Indicator
- The first two bits PQ(3) and PQ(4) are loaded from the Output Queue Grant Priority Level values.
- The other bits PQ(6) and PQ(7) are unchanged, as they belong to the data information contained in
the packet.
prssi.02.fm
Functional Description
Page 33 of 154
March 1, 2001
IBM [ IBM ]
