cynse70032 Cypress Semiconductor Corporation., cynse70032 Datasheet - Page 54

• Manufacturer Part Number: cynse70032
• Description: Network Search Engine
• Manufacturer: Cypress Semiconductor Corporation.

13.6
The hardware diagram of the Search subsystem of 31 devices is shown in Figure 13-31. Each of the four blocks in the diagram
represents a block of eight CYNSE70032 devices (except the last, which has seven devices). The diagram for a block of eight
devices is shown in Figure 13-32. The following are the parameters programmed into the 31 devices.
Note
30 in this case) must be programmed with LRAM = 1 and LDEV = 1. All other upstream devices (devices 0 through 29 in this
case) must be programmed with LRAM = 0 and LDEV = 0.
The timing diagrams referred to in this paragraph reference the Hit/Miss assumptions listed in Table 13-14. For the purpose of
illustrating timings, it is further assumed that the there is only one device with a matching entry in each of the blocks. Figure 13-33
shows the timing diagram for a Search command in the 136-bit-configured table (31 devices) for each of the eight devices in
block number 0. Figure 13-34 shows the timing diagram for Search command in the 68-bit-configured table (31 devices) for all
devices above the winning device in block number 1. Figure 13-35 shows the timing diagram for the globally winning device (the
winner within its own and all blocks) in block number 1. Figure 13-36 shows the timing diagram for all devices below the globally
winning device in block number 1. Figure 13-37, Figure 13-38, and Figure 13-39, respectively, show the timing diagrams of the
devices above globally winning device, the globally winning device, and the devices below the globally winning device for block
number 2. Figure 13-40, Figure 13-41, Figure 13-42, and Figure 13-43, respectively, show the timing diagrams of the devices
above the globally winning device, the globally winning device, and the devices below the globally winning device except the last
device (device 30) for block number 3, and then the last device (device 30) for block number 3.
The 136-bit Search operation is pipelined and executes as follows. Four cycles from the Search command, each of the devices
knows the outcome internal to it for that operation. In the fifth cycle after the Search command, the devices in a block arbitrate
for a winner from among them (a “block” being less than or equal to eight devices resolving the winner by using LHI[6:0] and
LHO[1:0] signalling mechanisms). In the sixth cycle after the Search command, the blocks of devices resolve the winning block
through the BHI[2:0] and BHO[2:0] signalling mechanisms. The winning device in the winning block is the global winning device
for a Search operation.
Table 13-14. Hit/Miss Assumptions
Document #: 38-02042 Rev. *E
• First 30 devices (devices 0–29): CFG = 01010101, TLSZ = 10, HLAT = 001, LRAM = 0, and LDEV = 0.
• 31st device (device 30): CFG = 01010101, TLSZ = 10, HLAT = 001, LRAM = 1, and LDEV = 1.
. All 31 devices must be programmed with the same value of TLSZ and HLAT. Only the last device in the table (device number
Search Number
136-bit Search on Tables Configured as ×136 using up to 31 CYNSE70032 Devices
Block 0
Block 1
Block 2
Block 3
Miss
Miss
Miss
Hit
1
Miss
Miss
Hit
Hit
2
Miss
Miss
Hit
Hit
3
CYNSE70032
Page 54 of 126
Miss
Miss
Miss
Miss
4