cynse70032 Cypress Semiconductor Corporation., cynse70032 Datasheet - Page 52

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

The following is the sequence of operation for a single 136-bit Search command (also see Subsection 12.2, “Commands and
Command Parameters” on page 19).
The host ASIC continues to drive CMDV high and to apply Search command code (10) on CMD[1:0]. CMD[5:2] must be driven
by the index of the comparand register pair for storing the 136-bit word presented on the DQ bus during cycles A and B. CMD[8:6]
signals must be driven with the SSR index 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 68-bit data ([67:0]) compared against all odd locations.
The logical 136-bit Search operation is shown in Figure 13-30. The entire table (eight devices of 136-bit entries) is compared to
a 136-bit word K (presented on the DQ bus in cycles A and B of the command) using the GMR and local mask bits. The GMR is
the 136-bit word specified by the even and odd global mask pair selected by the GMR Index in the command’s cycle A.
Document #: 38-02042 Rev. *E
CFG = 01010101, HLAT = 010, 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 to apply Search command code (10) on CMD[1:0]. CMD[5:2] must
must be driven with the index to the GMR pair for use in this Search operation. CMD[8:6] signals must be driven with the same
bits that will be driven by this device on SADR[21:19] if it has a hit. DQ[67:0] must be driven with the 68-bit data ([135:68]) in
order to be compared against all even locations. The CMD[2] signal must be driven to logic 0.
be driven by the index of the comparand register pair for storing the 136-bit word presented on the DQ bus during cycles A
and B. CMD[8:6] signals must be driven with the SSR index 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 68-bit data ([67:0]) compared against all
odd locations.
SADR[21:0]
|(LHI[6:0])
CMD[1:0]
CMD[8:2]
LHO[1:0]
CLK2X
PHS_L
ALE_L
CMDV
WE_L
OE_L
CE_L
SSV
SSF
Figure 13-29. Timing Diagram for 136-bit Search Device Number 7 (Last Device)
DQ
0
0
0
0
1
0
cycle
Search1
A B A B A B A B
1
A B A B A B A B
01
D1
cycle
Search2
2
01
D2
cycle
Search3
3
01
D3
cycle
4
Search4
01
D4
cycle
5
cycle
6
cycle
7
(Miss on
this device.)
z
z
Search1
z
cycle
8
(Miss on
this device.)
Search2
cycle
(Local but not
global winner.)
9
A4
Search3
z
z
cycle
10
0
1
0
(Global winner.)
Search4
1
1
CYNSE70032
0
0
Page 52 of 126