CYNSE70032 Datasheet, PDF (71/126 Pages) Cypress Semiconductor – Network Search Engine

CYNSE70032
Table 13-18. Shift of SSF and SSV from SADR (continued)
HLAT
100
101
110
111
Number of CLK Cycles
4
5
6
7
13.8 272-bit Search on Tables Configured as ×272 and Using up to Eight CYNSE70032 Devices
The hardware diagram of the Search subsystem of eight devices is shown in Figure 13-48. The following are the parameters
programmed into the eight devices.
• First seven devices (devices 0–6): CFG = 10101010, TLSZ = 01, HLAT = 000, LRAM = 0, and LDEV = 0.
• Eighth device (device 7): CFG = 10101010, TLSZ = 01, HLAT = 000, LRAM = 1, and LDEV = 1.
Note. All eight devices must be programmed with the same value of TLSZ and HLAT. Only the last device in the table must be
programmed with LRAM = 1 and LDEV = 1 (device number 7 in this case). All other upstream devices must be programmed with
LRAM = 0 and LDEV = 0 (devices 0 through 6 in this case).
Figure 13-49 shows the timing diagram for a Search command in the 272-bit-configured table of eight devices for device
number 0. Figure 13-50 shows the timing diagram for a Search command in the 272-bit-configured table of eight devices for
device number 1. Figure 13-51 shows the timing diagram for a Search command in the 272-bit-configured table of eight devices
for device number 7 (the last device in this specific table). For these timing diagrams, three 272-bit searches are performed
sequentially. The following Hit/Miss assumptions were made, as shown in Table 13-19.
Table 13-19. Hit/Miss Assumptions
Search Number
Device 0
Device 1
Devices 2–6
Device 7
1
Hit
Miss
Miss
Miss
2
Miss
Hit
Miss
Miss
3
Miss
Miss
Miss
Miss
Document #: 38-02042 Rev. *E
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