IBM PowerPRS Q-64G
Preliminary
Packet Routing Switch
Figure 3-2. Ingress Idle Packet Format
High Channel Packet
Byte 0
H0
Byte 1
H1
Byte 2
H2
Byte 3
D21.5
Byte 4
D21.5
Byte 5
SCC
Byte 6
FC
Byte 7
K28.1
Byte 8
D21.5
Byte 9
D21.5
Master LU
D21.5
D21.5
D21.5
D21.5
D21.5
D21.5
D21.5
K28.1
D21.5
D21.5
7 Slave LUs
Low Channel Packet
Byte 0
H0
Byte 1
H1
Byte 2 Byte 3
Byte 4
D21.5
Byte 5
SCC
Byte 6
FC
Byte 7
K28.5
Byte 8
D21.5
Byte 9
D21.5
H2
D21.5
Master LU
7 Slave LUs
Notes:
D21.5
D21.5
D21.5
D21.5
D21.5
D21.5
D21.5
K28.5
D21.5
D21.5
1. H0, H1, and H2 are packet header bytes.
2. D21.5, K28.1, and K28.5 characters are 8b/10b control characters. K28.1 and K28.5 characters are used for link
synchronization (byte alignment and packet clock recovery) and supervision (byte alignment and synchronization
lost). D21.5 characters guarantee continuous transition on the line.
3. SCC is side communication channel data. Bits 4:7 are copies of bits 0:3.
4. FC is flow control information in addition to that transmitted in the packet header.
Table 3-1. Ingress Idle Packet, Byte H0
Information Carried
Bits 2:3
Byte
Bit 0
Bit 1
Bits 4:5
Color
Bits 6:7
Subport grant type/
subport flywheel
status (bit 0 of
three bits)
Subport grant type/
subport flywheel
status (bits 1:2
of three bits)
H0
Parity
Protection
Protection
(high channel)
H0
Grant priority
flywheel status
Reserved
Parity
Color
(low channel)
Table 3-2. Ingress Idle Packet, Byte H0 Field Descriptions (Page 1 of 2)
Bit(s)
Field Name
Description
Subport Grant
Type/Subport
Flywheel Status
(high channel)
See the description for bits 6:7.
Reserved.
0
Reserved
(low channel)
1
Parity
Header parity.
2:3
Protection
Must be set to ‘00’ for idle packets.
Note: On the high channel, bits 0, 6, and 7 of byte H0 carry the three-bit subport grant type/subport flywheel status. On the low chan-
nel, bit 0 is reserved, and bits 6:7 carry the subport grant type/subport flywheel status.
prsq-64g.01.fm
December 20, 2001
Functional Description
Page 31 of 199
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