IBM3229P2035
Advance
IBM Packet Routing Switch Serial Interface Converter
3.6.4.2 Data Packets
The data packet format can be made of LUs of 16 to 20 bytes long depending on the configuration register.
Data Packet Format Switch 8x8 and 16x16
Master LU
Slave LU
Slave LU
Slave LU
PQ
D
OQG0
OQG1
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
Data Packet Format Switch 32x32
Master LU
Slave LU
Slave LU
Slave LU
PQ
D
OQG0
OQG1
OQG2
OQG3
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
3.6.5 IBM 28.4G Packet Routing Switch (switch) in band Output Queue Grant Information
Bytes BM1 and BM2 carry the output queue grant coming from the switch. This information is carried for all
16 output ports simultaneously for a given priority. Consecutive packets, either data or idle, carry a different
priority of the output queue grant bits, cycling from 0 to the highest priority value that is enabled. For instance,
when two priorities are enabled, it takes two packets to transmit the output queue grant information.
Table 10: Output Queue Grant Bit Map Fields
UTOPIA-3 Bit Notation
DASL/IBM 28.4G Packet Routing Switch Bit
Output Queue Grant 1
7
6
5
2
4
3
3
4
2
5
1
6
0
7
0
1
Port 0
Port 8
Port 1
Port 9
Port 2
Port 10
Port 3
Port 11
Port 4
Port 12
Port 5
Port 13
Port 6
Port 14
Port 7
Port 15
Output Queue Grant 2
When a bit of this OQG field is set to '1', data can be sent to the corresponding output queue. When set to '0'
no data should be sent to that output queue. The switch sets (8-port mode) OQG1 to 'FF' when operating in
internal speed expansion. If a yellow packet is detected when detection is enabled, an interruption is
reported. If detection is not enabled the yellow packet is considered an idle packet.
prssi.02.fm
Functional Description
Page 41 of 154
March 1, 2001
IBM [ IBM ]
