Compaq EV68A specifications Dual-Data Rate SSRAMs, Table E-4 Dual-Data Rate Ssram Data Pin Usage

Models: EV68A

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Dual-Data Rate SSRAMs

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

21264/EV68A Signal Name or Board Connection

Late-Write SSRAM Tag Pin Name

 

 

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

CK_L

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

VREF1_H

 

VREF2_H

Set from board (implementation dependent)

ZQ_H

BcTagValid_H

DQx

BcTagDirty_H

DQx

BcTagShared_H

DQx

Unconnected

TMS_H

Unconnected

TDI_H

Unconnected

TCK_H

Unconnected

TDC_H

 

 

E.3 Dual-Data Rate SSRAMs

Table E–4provides the data pin connections between dual-data rate SSRAMs and the 21264/EV68A or the system board. Table E–5provides the same information for the tag pins.

Data Pin Usage

Table E–4 Dual-Data Rate SSRAM Data Pin Usage

21264/EV68A Signal Name or Board

 

Connection

Dual-Data Rate SSRAM Data Pin Name

 

 

BcAdd_H[21:4]

SA_H[17:0]

BcData_H[33:20]/

DQx

BcCheck_H[15:0]

 

BcLoad_L

LD_L (B1)

BcDataWr_L

R/W_L(B2)

From board, pulled up to VDD

LBO_L

From board, pulled down to VSS

Q_L

BcDataInClk_H

CQ_H

BcDataOutClk_H

CK_H

BcDataOutClk_L

CK_L

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

VREF1_H

voltage

VREF2_H

Set from board (implementation-dependent)

ZQ_H

Unconnected or terminated

CQ_L

From board, pulled up toVDD

TCK_H

Unconnected

TDO_H

21264/EV68A Hardware Reference Manual

21264/EV68A-to-Bcache Pin Interface E–3

Page 323
Image 323
Compaq EV68A specifications Dual-Data Rate SSRAMs, Table E-4 Dual-Data Rate Ssram Data Pin Usage