KE5BLME008 데이터 시트보기 (PDF) - KAWASAKI MICROELECTRONICS

부품명

상세내역

제조사

KE5BLME008

Longest Match Engine

KAWASAKI MICROELECTRONICS 

Kawasaki LSI

8K Longest Match Search Engine (KE5BLME008)

PRELIMINARY

4.3. Initialization

After resetting the device, execute the Initialize command, which is required for data to be

properly inserted into the device. The execution of this command requires approximately

7.8µs at 66MHz clock. Before proceeding with the subsequent commands, check anew by

monitoring the CCMPN pin whether the initialization process has been completed.

4.4. Data Insertion

To enter data in the table, use the Insert command. Ensure that the IP address is set to WR0-

1, the associated data to WR2, and PL (prefix length –1) to WR4.

Example:

When inserting 192.1.2.0/24 with associated data 3456h, enter the following.

WR0: 0200h (2.0)

WR1: C001h (192.1)

WR2: 3456h

WR4: 0017h (23 = 24–1)

Ensure that the value entered in WR4 is the prefix-length minus 1, not the prefix-length

itself.

The completion of the Insert command is confirmed by a low signal on the CCMPN pin.

Proceed with the subsequent commands after checking the CCMPN status.

LME008 is capable of storing the exact data match, i.e., the entry data hitting only when all

the 32 bits coincide with the input key data. When inserting exact match data, set 31 to WR4

(PL). This particular function is useful for storing the host address in the table.

4.5. Search

To conduct a longest match search, apply data to INP [31:0], and set a SRCHN pin Low (see

Fig.4.1). At the 22nd clock after starting a search, MDONEN will be changed to Low,

allowing both MLE [4:0] and HON to output. MLE [4:0] output should be equal to the match

length minus one. That is to say, MLE [4:0] is the maximum value of the match length of a

search key minus 1. The HON status indicates a lookup result, with Low a hit, and High as a

miss hit. MDONEN will revert from High to Low after 4 clock cycles, while both MLE [4:0]

and HON will be held until the next lookup result.

At the 28th clock after starting a search, ODONEN will be changed into Low, allowing OUT

[15:0] to output associated data. If the search results in a miss match, the value pre-registered

at the default associated data will be returned. ODONEN will revert from High to Low after

4 clock cycles, whereas OUT [15:0] will be held until the next result. For instance, let us

assume the presence of the following data in the table:

Version1.0.1

Proprietary and Confidential

9

Share Link: