Late-Write Non-Bursting SSRAMs

Table E–1 Bcache Forwarding Clock Pin Groupings (Continued)

Pad and Pin

Input Clock

Output Clocks

 

 

 

BcTagShared_H

BcTagInClk_H

BcTagOutClk_x

BcTagDirty_H

BcTagInClk_H

BcTagOutClk_x

BcTagValid_H

BcTagInClk_H

BcTagOutClk_x

 

 

 

E.2 Late-Write Non-Bursting SSRAMs

Table E–2provides the data pin connections between late-write non-bursting SSRAMs and the 21264/EV68A or the system board. Table E–3provides the same information for the tag pins.

Data Pin Usage

Table E–2 Late-Write Non-Bursting SSRAMs Data Pin Usage

21264/EV68A Signal Name or Board Connection

Late-Write SSRAM Data Pin Name

 

 

BcAdd_H[21:4]

SA_H[17:0]

BcDataOutClk_H[3:0]

CK_H

Set from board to 1/2 the 21264/EV68A core voltage

CK_L

BcData_H[127:0]/BcCheck_H[15:0]

DQx

BcDataWr_L

SW_L

Unconnected

Tck_H

Unconnected

Tdo_H

Unconnected

Tms_H

Unconnected

Tdi_H

From board, pull down to VSS

G_L

From board, pull down to VSS

SBx_L

From board, pull down to VSS or BcDataOE_L

SS_L (Vendor dependent)

 

 

Tag Pin Usage

Unused Bcache tag pins should be pulled to ground through a 200-ohm resistor.

Table E–3 Late-Write Non-Bursting SSRAMs Tag Pin Usage

21264/EV68A Signal Name or Board Connection

Late-Write SSRAM Tag Pin Name

BcAdd_H[22:6]

SA_H[16:0]

BcTag_H[42:20]

DQx

BcTagOE_L or from board, pull down to VSS

SS_L (Vendor dependent)

BcTagWr_L

SW_L

From board, pull down toVSS

SBx_L

BcTagOutClk_H

CK_H

E–221264/EV68A-to-Bcache Pin Interface

21264/EV68A Hardware Reference Manual

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Compaq EV68A specifications Late-Write Non-Bursting SSRAMs, Data Pin Usage, Tag Pin Usage