IBM PowerPRS Q-64G
Packet Routing Switch
Preliminary
Figure 3-4. Ingress Service Packet Format
High Channel Packet
Byte 0
H0
Byte 1
H1
Byte 2
H2/D
Byte 3
D
Byte 4
D
Byte 5
D
Byte 6
D
Byte 7
D
Byte 8
D
Byte 9
D
Master LU
D
D
D
D
D
D
D
D
D
D
7 Slave LUs
Low Channel Packet
Byte 0
H0
Byte 1
H1
Byte 2 Byte 3
Byte 4
D
Byte 5
D
Byte 6
D
Byte 7
D
Byte 8
D
Byte 9
D
H2/D
D
Master LU
7 Slave LUs
Notes:
D
D
D
D
D
D
D
D
D
D
1. H0, H1, and H2 are packet header bytes. Bytes H1 and H2 are reserved and must be set to x‘00’. (H2 exists only
in the 512-Gbps configuration.)
2. For command service packets, D is service data. For event service packets, these bytes are ignored by the
PowerPRS Q-64G and can be filled with any character.
Table 3-8. Ingress Service Packet, Byte H0
Information Carried
Bits 2:3
Byte
Bit 0
Bit 1
Bits 4:6
Bit 7
H0
Reserved
Parity
Protection
Service packet type
Reserved
(high and low channel)
Table 3-9. Ingress Service Packet, Byte H0 Field Descriptions
Bit(s)
0
Field Name
Reserved
Parity
Description
Reserved.
1
Header parity.
2:3
Protection
Must be set to ‘00’ for service packets.
Specifies the type of service packet:
100
101
110
111
Event-1 service packet
Command service packet
Event-2 service packet
Reserved
4:6
7
Service Packet Type
Reserved
Reserved.
3.3.6 Flow Control Flywheels for Grants Carried in Egress Packets
There are four flow control flywheels associated with the grants carried in egress packets:
• Extended output queue grant flywheel
• Output queue grant priority flywheel
• Subport grant type/priority flywheel
• Subport grant port flywheel
Functional Description
Page 36 of 199
prsq-64g.01.fm
December 20, 2001
IBM [ IBM ]
