cynse70032 Cypress Semiconductor Corporation., cynse70032 Datasheet - Page 75

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

The following is the sequence of operation for a single 272-bit Search command (also see “Commands and Command Param-
eters” on page 19).
Note
The GMR index in cycle A selects a pair of GMRs in each of the eight devices that apply to DQ data in cycles A and B. The GMR
index in cycle C selects a pair of GMRs in each of the eight devices that apply to DQ data in cycles C and D.
Document #: 38-02042 Rev. *E
CFG = 10101010, HLAT = 000, TLSZ = 01, LRAM = 1, LDEV = 1.
Note: |(LHI[6:0]) stands for the boolean ‘OR’ of the entire bus LHI[6:0].
Note: Each bit in LHO[1:0] is the same logical signal.
• Cycle A: The host ASIC drives CMDV high and applies Search command code (10) on CMD[1:0] signals. CMD[5:3] signals
• Cycle B: The host ASIC continues to drive CMDV high and applies Search command code (10) on CMD[1:0]. The DQ[67:0]
• Cycle C: The host ASIC drives CMDV high and applies Search command code (10) on CMD[1:0] signals. CMD[5:3] signals
• Cycle D: The host ASIC continues to drive CMDV high and applies Search command code (10) on CMD[1:0]. CMD[8:6] signals
must be driven with the index to the GMR pair used for bits [271:136] of the data being searched in this operation. DQ[67:0]
must be driven with the 68-bit data ([271:204]) to be compared against all locations 0 in the four-word 68-bit page. The CMD[2]
signal must be driven to logic 1.
is driven with the 68-bit data ([203:136]) to be compared against all locations 1 in the four 68-bits-word page.
must be driven with the index to the GMR pair used for bits [135:0] of the data being searched. CMD[8:6] signals must be
driven with the bits that will be driven on SADR[21:19] by this device if it has a hit. DQ[67:0] must be driven with the 68-bit data
([135:68]) to be compared against all locations 2 in the four 68-bits-word page. The CMD[2] signal must be driven to logic 0.
must be driven with the index of the SSR that will be used for storing the address of the matching entry and the hit flag (see
page 14 for the description of SSR[0:7]). The DQ[67:0] is driven with the 68-bit data ([67:0]) to be compared to all locations 3
in the four 68-bits-word page. CMD[5:2] is ignored because the Learn instruction is not supported for ×272 tables.
. For 272-bit searches, the host ASIC must supply four distinct 68-bit data words on DQ[67:0] during cycles A, B, C, and D.
SADR[21:0]
|(LHI[6:0])
CMD[1:0]
CMD[8:2]
LHO[1:0]
CMD[2]
CLK2X
PHS_L
ALE_L
CMDV
Figure 13-51. Timing Diagram for 272-bit Search Device Number 7 (Last Device)
WE_L
OE_L
CE_L
SSV
SSF
DQ
Note
0
0
1
0
0
0
. CMD[2] = 1 signals that the search is a x272 bit search. CMD[8:3] in this cycle is ignored.
cycle
A B A B A B A B
A B C D A B C D
1
Search1
cycle
01
D1
2
cycle
3
Search2
D2
cycle
01
4
cycle
A B A B
A B C D
5
Search3
D3
cycle
01
6
1
(Miss on
this device.)
cycle
Search1
7
z
z
z
z
z
cycle
8
0
0
(Miss on
this device.)
Search2 Search3
cycle
9
z
z
z
z
z
cycle
10
(Global
miss.)
0
0
1
0
0
CYNSE70032
1
0
Page 75 of 126