IBM3229P2035
Advance
IBM Packet Routing Switch Serial Interface Converter
32x32 Switch LU Output Format:
Container
C00
C01
C02
C03
C04
C05
D
C06
D
C07
D
C08
D
C09
D
C10
D
C11
D
C12
D
C13
D
C14
D
C15
D
Master LU0 PQ
BM1 BM2 BM3 BM4
Slave LU1
Slave LU2
Slave LU3
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
When the switch is in 32x32 mode, all bytes of the Bitmap are used (BM1, BM2, BM3, and BM4) for both port
addressing and to compute the header parity. When the switch is in 16x16 mode, only BM1 and BM2 are
used while BM3 and BM4 are considered as payload and are ignored for the computation of the header
parity. When the switch is in 08x08 mode, only BM1 is used while BM2 must be ’00’ so it does not impact the
computation of the parity in packet qualifier.
3.3.1.3 Port Addressing
The following table shows the switch output port addressing (a binary 1 in the bit map field indicates that the
packet should be sent to the corresponding switch output port).
Table 3: Output Port Bitmap Fields
UTOPIA-3 Bit Notation
7
6
1
5
2
4
3
3
4
2
5
1
6
0
7
IBM Packet Routing Switch/
DASL Bit
0
Output port bit map 1
Output port bit map 2
Output port bit map 3
Output port bit map 4
Port 0
Port 8
Port 1
Port 9
Port 2
Port 10
Port 18
Port 26
Port 3
Port 11
Port 19
Port 27
Port 4
Port 12
Port 20
Port 28
Port 5
Port 13
Port 21
Port 29
Port 6
Port 14
Port 22
Port 30
Port 7
Port 15
Port 23
Port 31
Port 16
Port 24
Port 17
Port 25
3.3.2 Nested TxPause Extraction
In IBFC, The bits PQ (26,27 and 30,31) of the packet qualifier are monitored to extract the converter egress
flow control information (TxPause). The TxPause information is used by the PE to flow control the switch’s
output port. The converter interprets those bits and translates them into Sent Grant to the switch. The use of
TxPause is dependent upon the setting of register @C8 bit 30 of the configuration table register. When Bit 3
(Send Grant per Priority) of configuration register table @C4 is not enabled, any bit set to '0' in the TxPause
field is sufficient to stop transmission to the attached protocol engine.
prssi.02.fm
Functional Description
Page 29 of 154
March 1, 2001
IBM [ IBM ]
