M7020 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

MFG CO.

M7020

32K x 68-bit Entry NETWORK SEARCH ENGINE

STMicroelectronics 

M7020R

SEARCH-Successful Registers (SSR[0:7])

The device contains eight search successful reg-

isters (SSRs) to hold the index of the location

where a successful search occurred. The format of

each register is described in Table 9. The

SEARCH command specifies which SSR stores

the index of a specific SEARCH command in Cy-

cle B of the SEARCH Instruction. Subsequently,

the host ASIC can use this register to access that

data array, mask array, or external SRAM using

the index as part of the indirect access address

(see Table 19, page 32 and Table 22, page 35).

The device with a valid bit set performs a READ or

WRITE operation. All other devices suppress the

operation.

Table 9. SEARCH-Successful Register (SSR) Description

Field

Range

Initial Value

Description

INDEX

[14:0]

Index. This is the address of the 68-bit entry where a successful

search occurs. The device updates this field only when a search is

X

successful. If a hit occurs in a 136-bit entry-size quadrant, the LSB is

’0.’ If a hit occurs in a 272-bit entry size quadrant, the two LSBs are

’00.’ This index updates if the device is either a local or global winner

in a SEARCH operation.

–

[30:15]

0

Reserved.

VALID

[31]

Valid. During SEARCH operation in a depth-cascaded configuration,

0

the device that is a global winner in a match sets this bit to '1.' This bit

updates only when the device is a global winner in a SEARCH

operation.

–

[67:32]

0

Reserved.

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