Pin Assignments

Table 3–3 21264/EV68A Signal Descriptions by Function (Continued)

Signal

Type

Count

Description

 

 

 

 

Reset_L

I_DA

1

System reset. This signal protects the 21264/EV68A from

 

 

 

damage during initial power-up. It must be asserted until

 

 

 

DCOK_H is asserted. After that, it is deasserted and the

 

 

 

21264/EV68A begins its reset sequence.

SromClk_H

O_OD_TP

1

Serial ROM clock.

SromData_H

I_DA

1

Serial ROM data.

SromOE_L

O_OD_TP

1

Serial ROM enable.

Tck_H

I_DA

1

IEEE 1149.1 test clock.

Tdi_H

I_DA

1

IEEE 1149.1 test data-in signal.

Tdo_H

O_OD_TP

1

IEEE 1149.1 test data-out signal.

TestStat_H

O_OD_TP

1

Test status pin.

Tms_H

I_DA

1

IEEE 1149.1 test mode select signal.

Trst_L

I_DA

1

IEEE 1149.1 test access port (TAP) reset signal.

 

 

 

 

3.3Pin Assignments

The 21264/EV68A package has 587 pins aligned in a pin grid array (PGA) design. There are 380 functional signal pins, 1 dedicated 2.5-V pin for the PLL, 112 ground VSS pins, and 94 VDD pins. Table 3–4lists the signal pins and their corresponding pin grid array (PGA) locations in alphabetical order for the signal type. Table 3–5lists the pin grid array locations in alphabetical order.

Table 3–4 Pin List Sorted by Signal Name

Signal Name

PGA Location

Signal Name

PGA Location

Signal Name

PGA Location

 

 

 

 

 

 

BcAdd_H_10

B30

BcAdd_H_11

D30

BcAdd_H_12

C31

BcAdd_H_13

H28

BcAdd_H_14

G29

BcAdd_H_15

A33

BcAdd_H_16

E31

BcAdd_H_17

D32

BcAdd_H_18

B34

BcAdd_H_19

A35

BcAdd_H_20

B36

BcAdd_H_21

H30

BcAdd_H_22

C35

BcAdd_H_23

E33

BcAdd_H_4

B28

BcAdd_H_5

E27

BcAdd_H_6

A29

BcAdd_H_7

G27

BcAdd_H_8

C29

BcAdd_H_9

F28

BcCheck_H_0

F2

BcCheck_H_1

AB4

BcCheck_H_10

AW1

BcCheck_H_11

BD10

BcCheck_H_12

E45

BcCheck_H_13

AC45

BcCheck_H_14

AT44

BcCheck_H_15

BB36

BcCheck_H_2

AT2

BcCheck_H_3

BC11

BcCheck_H_4

M38

BcCheck_H_5

AB42

BcCheck_H_6

AU43

BcCheck_H_7

BC37

BcCheck_H_8

M8

BcCheck_H_9

AA3

BcData_H_0

B10

BcData_H_1

D10

BcData_H_10

L3

BcData_H_100

D42

BcData_H_101

D44

BcData_H_102

H40

BcData_H_103

H42

BcData_H_104

G45

BcData_H_105

L43

3–8

Hardware Interface

21264/EV68A Hardware Reference Manual

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Compaq EV68A specifications Pin Assignments, Pin List Sorted by Signal Name