Compaq specifications 21264/EV67 Signal Names and Functions, Signal Pin Types Definitions

Models: 21264 EV67

1 356
Download 356 pages 49.13 Kb
Page 71
Image 71

21264/EV67 Signal Names and Functions

3.2 21264/EV67 Signal Names and Functions

Table 3–1defines the 21264/EV67 signal types referred to in this section.

Table 3–1 Signal Pin Types Definitions

Signal Type

Definition

 

 

Inputs

 

 

 

I_DC_REF

Input DC reference pin

I_DA

Input differential amplifier receiver

I_DA_CLK

Input clock pin

 

 

Outputs

 

O_OD

Open drain output driver

O_OD_TP

Open drain driver for test pins

O_PP

Push/pull output driver

O_PP_CLK

Push/pull output clock driver

 

 

Bidirectional

 

B_DA_OD

Bidirectional differential amplifier receiver with open drain output

B_DA_PP

Bidirectional differential amplifier receiver with push/pull output

 

 

Other

 

Spare

Reserved to Compaq1

NoConnect

No connection — Do not connect to these pins for any revision of the

 

21264/EV67. These pins must float.

 

 

1All Spare connections are Reserved to Compaq to maintain compatibility between passes of the chip. Designers should not use these pins.

Table 3–2lists all signal pins in alphabetic order and provides a full functional descrip- tion of the pins. Table 3–4lists the signal pins and their corresponding pin grid array (PGA) locations in alphabetic order for the signal type. Table 3–5lists the pin grid array locations in alphabetical order.

Table 3–2 21264/EV67 Signal Descriptions

Signal

Type

Count

Description

 

 

 

 

BcAdd_H[23:4]

O_PP

20

These signals provide the index to the Bcache.

BcCheck_H[15:0]

B_DA_PP

16

ECC check bits for BcData_H[127:0].

BcData_H[127:0]

B_DA_PP

128

Bcache data signals.

BcDataInClk_H[7:0]

I_DA

8

Bcache data input clocks. These clocks are used with high

 

 

 

speed SDRAMs, such as DDRs, that provide a clock-out with

 

 

 

data-output pins to optimize Bcache read bandwidths. The

 

 

 

21264/EV67 internally synchronizes the data to its logic with

 

 

 

clock forward receive circuits similar to the system interface.

BcDataOE_L

O_PP

1

Bcache data output enable. The 21264/EV67 asserts this signal

 

 

 

during Bcache read operations.

Alpha 21264/EV67 Hardware Reference Manual

Hardware Interface 3–3

Page 71
Image 71
Compaq 21264/EV67 Signal Names and Functions, Signal Pin Types Definitions, 21264/EV67 Signal Descriptions