PGA and QFP Pinout Offerings for the IBM 486 DX4 ®

Application Note

Author: Scott Pheasant

Revision Summary: This is the initial release of this Application Note

Introduction

This paper explains which pinout options are available for the IBM 486 DX4 microproces- sor and IBM's reasons for providing multiple pinouts in the same package.

The IBM 486 DX4 processor is being offered in one 208-pin CQFP (Ceramic Quad Flat Pack) package pinout and two 168-pin PGA (Pin Grid Array) package pinouts.

Reasons For Providing Multiple PGA Pinouts

The IBM 486 DX4 is provided in two PGA pinouts:

1. IBM 486 DX2 pinout (identical to the current IBM 486 DX2) 2. ® 486DX4-like pinout (Intel 486DX4-like pinout + Write-Back cache pins)

Either pinout is functionally equivalent, in fact both are built with identical chips.

The IBM 486 DX2 pinout is being offered to allowed current IBM 486 DX2 customers to easily upgrade to an IBM 486 DX4 microprocessor. No motherboard changes are necessary. A simple BIOS change may be required to recognize the DX4 processor-id, as it is different from the DX2.

The IBM 486 DX4 pinout is being offered for new motherboard designs that support the Intel 486DX4 microprocessor. These motherboards must be capable of supporting the on-chip Write- Back L1 cache to gain maximum performance from the IBM 486 DX4. The addition of HITM# and INVAL are the two Write-Back pins which are unique to the IBM 486 DX4 and not present with the Intel 486DX4. The Intel P24D microprocessor includes the HITM# and INVAL pins as it supports Write-Back.

Page 1 of 7 September 11, 1995 Fax # 40024 CQFP Option

The pinout for the IBM 486 DX4 in a QFP package has only one additional functional pin versus the IBM 486 DX2 QFP product. The pin is #11 and its label is CLKMUL.

All technical data for this product can be found in the Blue Lightning 486 DX2 Databook and the IBM 486 DX4 Addendum to the databook.

The differences among the various IBM and Intel CQFP products are best summarized by the following table:

Pin # IBM DX2 IBM DX4 Intel DX4 Intel P24D (Write-Back Enhanced DX2) 3 NC NC Vcc5 Vcc 11 NC CLKMUL CLKMUL INC 18 NC NC TCK TCK 58 WM_RST WM_RST SRESET SRESET 59 SMADS# SMADS# SMIACT# SMIACT# 63 RPLSET0 RPLSET0 NC HITM# 64 RPLSET1 RPLSET1 NC WB/WT# 67 INVAL INVAL NC NC 68 NC NC TDO TDO 70 RPLVAL# RPLVAL# NC CACHE# 71 SUSPA# SUSPA# NC INV 73 SUSP# SUSP# STPCLK# STPCLK# 96 HITM# HITM# NC NC 167 NC NC TMS TMS 168 NC NC TDI TDI

The following page contains the pinout assignments for the CQFP Package.

Page 2 of 7 September 11, 1995 Fax # 40024 # # # K T K C S # s C O c A S s c s c # c s c 0 c s c 1 s 2 c 3 4 c s 5 6 c 7 s c 8 9 0 c c 1 2 3 4 s s O L c L D 2 s c s c 3 4 5 P 6 7 c 8 s c 9 1 c s c 1 s 1 c 1 1 c s 1 1 c 1 s c C C 1 1 2 c c 2 2 2 2 s V L P V B A A V V V V A A A U A A V A V V A A V V V A V A V A A V V A A V A V V N N A A A V V A A A A V

8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 0 0 0 0 0 0 0 0 0 9 9 9 9 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 8 7 7 7 7 7 7 7 7 7 7 6 6 6 6 6 6 6 6 6 6 5 5 5 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 156 Vss Vss 1 155 Vcc Vcc 2 154 A25 NC 3 153 A26 PCHK# 4 152 A27 BRDY# 5 151 A28 BOFF# 6 150 Vcc BS16# 7 149 A29 BS8# 8 148 A30 Vcc 9 147 A31 Vss 10 146 Vss CLKMUL 11 145 DP0 RDY# 12 144 D0 KEN# 13 143 D1 Vcc 14 142 D2 Vss 15 141 D3 HOLD 16 140 D4 AHOLD 17 139 Vcc NC 18 138 Vss Vcc 19 137 Vcc Vcc 20 136 Vcc Vss 21 IBM 486 DX4 135 Vss Vcc 22 134 Vcc Vcc 23 133 Vcc CLK 24 132 Vss Vcc 208-Lead CQFP 25 131 Vcc HLDA 26 130 D5 W/R# 27 129 D6 Vss 28 (Top VIEW) 128 Vcc Vcc 29 127 NC BREQ 30 126 D7 BE0# 31 125 DP1 BE1# 32 124 D8 BE2# 33 123 D9 BE3# 34 122 Vss Vcc 35 121 Vcc Vss 36 120 Vss M/IO# 37 119 D10 Vcc 38 118 D11 D/C# 39 117 D12 PWT 40 116 D13 PCD 41 115 Vss Vcc 42 114 Vcc Vss 43 113 D14 Vcc 44 112 D15 Vcc 45 111 Vcc EADS# 46 110 Vss A20M# 47 109 DP2 RESET 48 108 D16 FLUSH# 49 107 Vss INTR 50 106 Vcc NMI 51 105 Vss Vss 52 0 1 2 3 4 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 0 0 0 0 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 1 1 1 1 1

s c s c s T # c s c 0 1 I# # L C c # # # # 1 0 s c 9 8 c s c 7 6 5 c 4 s c 3 3 2 1 s c # s c 0 9 8 c 7 s s c s c s S S c s c T T R A N c L A E P 3 3 s c 2 2 c s c 2 2 2 c 2 s c P 2 2 2 s c M s c 2 1 1 c 1 s V V V V V R D V V V E E M R V V A P N S D D V V D D V V V D D D V D V V D D D D V V T V V D D D V D V _ A S S S E N V S N U I M L L F I L U G S H M P P P S I W S R R R

Page 3 of 7 September 11, 1995 Fax # 40024 PGA (IBM 486 DX2 Pinout) Option:

All technical data for this product can be found in the Blue Lightning 486 DX2 Databook and the IBM 486 DX4 Addendum to the databook.

The differences among the various IBM and Intel PGA products are best summarized by the following table:

Pin # IBM DX2 IBM DX4 IBM DX4 Intel DX4 Intel DX2 (IBM DX2 pin-out) (Intel DX4 pin-out, Write-Back Enhanced with W/B) or P24D A3 NC NC NC TCK TCK A10 SUSPA# SUSPA# INVAL INC INV A12 SMI# SMI# HITM# INC HITM# A13 RPLSET1 RPLSET1 SUSPA# INC INC A14 NC NC NC-(TDI) TDI TDI B10 NC NC SMI# SMI# SMI# B12 NC NC RPLSET1 INC CACHE# B13 WM_RST WM_RST RPLVAL# INC WB/WT# B14 NC NC RPLSET0 TMS TMS B16 NC NC NC-(TDO) TDO TDO C10 SMADS# SMADS# WM_RST SRESET SRESET C12 RPLSET0 RPLSET0 SMADS# SMIACT# SMIACT# C13 RPLVAL# RPLVAL# NC-(TEST) NC NC G15 SUSP# SUSP# SUSP# STPCLK# STPCLK# J1 NC NC NC Vcc5 Vcc R17 HITM# HITM# CLKMUL CLKMUL INC S4 INVAL INVAL NC-(VSS) VOLTDET NC

The following page contains the pinout assignments for the IBM DX2 PGA pinout option.

Page 4 of 7 September 11, 1995 Fax # 40024 PGA (IBM 486DX2 Pinout) Option

SRQPNMLKJHGFEDBA C

A27 A28 A31 D0 D2 Vss Vss Vss NC Vss Vss DP1 Vss D9 D11 D19 D20 1 1 A26 A25 Vss A29 D1 Vcc D6 Vcc D5 D3 Vcc D8Vcc D13 D18 D21 D22 2 2 A23 Vcc A17 A30 DP0 D4 D7 D14 D16 DP2 D12 D15 D10 D17 CLK Vss NC 3 3 INVAL Vss A19 Vcc Vss D23 4 4 A14 A18 A21 Vcc Vss DP3 5 5 Vss Vcc A24 D27 D25 D24 6 6 A12 A15 A22 D26 Vcc Vss 7 IBM 486DX4 7 Vss Vcc A20 D28 D31 D29 8 (IBM 486DX2 Pinout) 8 Vss Vcc A16 D30 Vcc Vss 9 168 PGA 9 Vss Vcc A13 SMADS# NC SUSPA# 10 (Top View) 10 Vss Vcc A9 UP# Vcc Vss 11 11 Vss A11 A5 RPLSET0 NC SMI# 12 12

A10 A8 A7 RPLVAL# WM_RST RPLSET1 13 13

Vss Vcc A2 FERR# NC NC 14 14 A6 A3 BREQ HLDA LOCK# D/C# PWT BE0# BE2# BRDY# SUSP# KEN# HOLD A20M# FLUSH# NMI IGNNE# 15 15 A4 BLAST# PLOCK# Vcc M/IO# Vcc Vcc Vcc BE1# Vcc Vcc RDY# Vcc BS8# RESET NC INTR 16 16 ADS# HITM# PCHK# Vss W/R# Vss VssVss PCD Vss Vss BE3# Vss BOFF# BS16# EADS# AHOLD 17 17

SRQPNMLKJHGFEDBA C

The following is the pin assignments for the IBM DX2 PGA pinout package:

Page 5 of 7 September 11, 1995 Fax # 40024 PGA (Intel 486DX4-like pinout) Option

SRQPNMLKJHGFEDBA C

A27 A28 A31 D0 D2 Vss Vss Vss NC Vss Vss DP1 Vss D9 D11 D19 D20 1 1 A26 A25 Vss A29 D1 Vcc D6 Vcc D5 D3 Vcc D8Vcc D13 D18 D21 D22 2 2 A23 Vcc A17 A30 DP0 D4 D7 D14 D16 DP2 D12 D15 D10 D17 CLK Vss NC 3 3 VOLTDET Vss A19 Vcc Vss D23 4 4 A14 A18 A21 Vcc Vss DP3 5 5 Vss Vcc A24 D27 D25 D24 6 6 A12 A15 A22 D26 Vcc Vss 7 IBM 486DX4 7 Vss Vcc A20 D28 D31 D29 8 (Intel 486DX4-like Pinout) 8 Vss Vcc A16 D30 Vcc Vss 9 168 PGA 9 Vss Vcc A13 WM_RST SMI# INV 10 (Top View) 10 Vss Vcc A9 UP# Vcc Vss 11 11 Vss A11 A5 SMADS# RPLSET1 HITM# 12 12

A10 A8 A7 NC RPLVAL# SUSPA# 13 13

Vss Vcc A2 FERR# RPLSET0 NC 14 14 A6 A3 BREQ HLDA LOCK# D/C# PWT BE0# BE2# BRDY# SUSP# KEN# HOLD A20M# FLUSH# NMI IGNNE# 15 15 A4 BLAST# PLOCK# Vcc M/IO# Vcc Vcc Vcc BE1# Vcc Vcc RDY# Vcc BS8# RESET NC INTR 16 16 ADS# CLKMUL PCHK# Vss W/R# Vss VssVss PCD Vss Vss BE3# Vss BOFF# BS16# EADS# AHOLD 17 17

SRQPNMLKJHGFEDBA C

The following is the pinout assignments for the Intel DX4 PGA pinout package:

Page 6 of 7 September 11, 1995 Fax # 40024 IBM Corporation 1995. All rights reserved. IBM and the IBM logo are registered trademarks of International Business Machines Corporation. IBM Microelectronics is a trademark of the IBM Corp. All other product and company names are trademarks/registered trademarks of their respective holders. 1995 IBM Corp.

This document may contain preliminary information and is subject to change by IBM without notice. IBM makes no representations or warranties the use of the information or applications shall be free of third party intellectual property claims and assumes no responsibility or liability for any use of the information contained herein. Nothing in this document shall operate as an express or implied license or indemnity under the intellectual property rights of IBM or third parties.

The products described in this document are not intended for use in implantation or other direct life support applications where malfunction may result in physical harm or injury to persons.

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Page 7 of 7 September 11, 1995 Fax # 40024