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Cyrix Foundry Agreements

Cyrix extended its wafer supply agreement with SGS-Thomson in 1994 (Originally formed in 1990). Under the new arrangement,
SGS-Thomson increased the number of wafers it produces for Cyrix and is allowed to make a certain
percentage of those same wafers for itself. In addition, Cyrix granted SGS-Thomson the right to use
certain Cyrix-designed chips as part of SGS-Thomson’s ASIC libraries. SGS-Thomson is allowed to
produce and sell such ASIC products under its own name in unlimited quantities, with Cyrix receiving
royalties from the sale of the devices. Also, Cyrix has the right to sell the SGS Thomson-designed ASICs
under its own name.


IBM and Cyrix announced a five-year agreement in (Sept 1993) calling for IBM to manufacture Cyrix's 486, 5x86,
and 6x86 MPUs. The two companies equally share the output of the Cyrix-designed chips. (Terminated in 1998 after The National Buy Out)

Differentiating between Cyrix and IBM Blue Lightning

It is difficult to distinguish IBM Blue Lightning CPU from Cyrix CPU. The behavior of both CPU is very similar to each other. The deference is that IBM Blue Lightning CPU supports MSR but Cyrix 486, 5x86 and 6x86 do not support it. This means that wrmsr instruction cause invalid opcode fault on Cyrix 486, 5x86 and 6x86, but does not on IBM Blue Lightning CPU. To detect invalid opcode by wrmsr, the following handler is prepared:

static volatile u_int trap_by_wrmsr;

inthand_t bluetrap;

movl $0xa8c1d, _trap_by_wrmsr
addl $2, (%esp)

If we have Cyrix 486, 5x86 or 6x86, the variable trap_by_wrmsr will be change by this handler. Once Cyrix CPU is detected by this method, we will check device ID register to distinguish it.

Time Line
4/1988 Jerry Rodgers Starts Cyrix with ex-TI Staff (30 total)
1989 Cyrix introduces the FasMath 83D87 math coprocessor, pin-compatible with Intel's 387.
1990 Cyrix introduces the FasMath 83S87 math coprocessor, pin-compatible with Intel's 387SX
1990 SGS-Thomson agreement (Based on 1979 Agrrement with Intel)
11/1991 Cyrix releses 387+
4/15/92 Cyrix announces 486SLC - It features an internal 32-bit data path, but with a 16-bit external data path. It includes a 1KB cache, but no coprocessor. Price is US$119
5/27/92 TI announces plans to market Cyrix-designed microprocessors
6/17/92 Cyrix announces 486DLC - It is comparable to Intel's i486, but with only a 1KB cache, and using only 600,000 transistors.
10/28/92 TI ships Cyrix-designed microprocessors
11/18/92 Cyrix announces 486S2/50
12/9/92 IBM previews 50MHz 486SLC2
3/3/93 Cyrix Launches 486S
4/19/93 IBM introduces the 20/40-MHz and 25/50-MHz 486SLC2 microprocessors. They feature a 16KB cache and optimized instruction set, but no internal math coprocessor, and only a 16-bit data path.
8/2/93 Cyrix introduces end-user upgrade processor for 386DX systems - Cyrix introduces the clock-doubled Cx486DRu2 microprocessor. Price is US$399.
8/2/93 IBM introduces Blue Lightning
8/23/93 Cyrix introduces 486DX compatible chip
10/25/93 Cyrix reveals design of M1
11/15/93 Texas Instruments reveals its first derivative chip based on Cyrix core
12/27/93 Cyrix introduces end-user upgrade processor for 486DX systems
6/20/94 IBM announces Cx486DX2 under IBM brand name
3/27/95 Cyrix samples the M1
6/19/95 TI introduced 80 MHz 486DX2
7/10/95 Cyrix reveals M1sc as 5x86
10/23/95 Cyrix M1 debuts as 6x86 - The chip is manufactured by IBM, and priced at US$450 each in quantities of 1000
10/23/95 Cyrix announces 5gx86
11/13/95 Cyrix announces 120 MHz 5x86 - available for US$160 each in quantities of 1000.
11/13/95 IBM announces own version of Cyrix 5x86 as 5x86C
11/13/95 SGS-Thomson announced 100 MHz 486DX4
11/13/95 TI introduced 100 MHz 486DX4
12/25/95 SGS-Thomson announcde 120 MHz 486DX4
2/12/96 Cyrix raised 6x86 to 133 MHz
2/12/96 IBM raised 6x86 to 133 MHz
6/17/96 Cyrix and IBM launch 100 MHz P200 version of 6x86
110-MHz P133+ CX6x86 microprocessor, for US$326.
60/120-MHz P150+ CX6x86 microprocessor, for US$451.
66/130-MHz P166+ CX6x86 microprocessor, for US$621.
10/28/96 Cyrix disclosed M2 at Microprocessor Forum
3/10/97 Cyrix introduced the MediaGX at 120 and 133 MHz
5/13/1997 Cyrix Sues Intel over the Pentium Pro
6/2/97 Cyrix replaced 6x86 with 6x86MX
7/14/97 Cyrix announces 166, 180 MHz MediaGX
8/1998 Cyrix Merges with National Semi
10/27/97 Cyrix describes Cayenne core
12/8/97 Cyrix describes the MXi
4/20/98 Cyrix renamed the 6x86MX the MII
6/1/98 Cyrix MII recaches performance level of PR333
11/16/98 Cyrix disclosed Jalapeno core and M3
5/10/99 Cyrix boosts M II to PR366.
5/31/99 Cyrix releases roadmap
5/31/99 National decides to sells Cyrix
7/12/99 VIA Technologies buys Cyrix

One of the 4 Court Cases Involving Cyrix

These cases (and the Intel vs ULSI case) were landmark
in the definition of patent exhaution law as applied to technology IP

Cyrix was sued 3 times by Intel, and one all 3 times

Cyrix sued Intel once (Intels Pentium Pro infringed on a Cyrix Patent)
Intel settled out of court for an undisclosed sum and granted Cyrix full cross liscesing with Intel.


NO. 4:92cv52


846 F. Supp. 522; 1994 U.S. Dist. LEXIS 3477; 32 U.S.P.Q.2D (BNA) 1890

January 21, 1994, Decided


Cyrix is entitled to judgment in its favor on its affirmative defenses of patent exhaustion and implied license based on the use or resale of its claim 1 microprocessors purchased from TI and ST.

Signed this day of January, 1994.


See Also
Cyrix Corp. v. SGS-Thomson Microelectronics, Inc., 77 F3d 1381 (Fed. Cir. 1996).

Cyrix Corporation and SGS-Thomson Microelectronics, Inc. v. Intel Corporation, 803 F. Supp. 1200, 1205-06 (E.D. Tex. 1992),

Cyrix CX486 S Series
(TI Produced)
Cyrix DRx2 Clock Doubled 386 Design
Cyrix Cx486DX DX2 and DX2 ST Produced
Ca486DX2 v-XX
IBM Made
Cyrix Cx486DX4
Cyrix 5x86 (and ST)
IBM Produced

(these can be on the tops as well)



DX 40

DX-2 80GP


5x86 Cyrix AND ST
P Process
1 3.6V
3 3.45V
4 3.6V
F Fab
B Burlington, Vermont
C Corbeil France
F Fish Kill, NY
J ?
K Bromont, Quebec
M Mask Revision
Y Year
4 1994
5 1995
WW Week
L Die Lot Code
P Process
3 486
5 586 0.65u
F Fab
M Mask Revision
Y Year
5 1995
6 1996
WW Week
L Die Lot Code


586-120 Samples October 30, production Nov 1995

1990 SGS-Thomson agreement
1995 .35u AT 586/686 5 Layer Phoenix

Cx486S40 AB1318B  
Cx486S33 AB1326F  
Cx486S40 AB2335D  
Cx486S40 DB2341B  
Cx486S40 DB2342B  
Cx486S25 DB2342D  
Cx486S33 DB2342J  
Cx486S40 DB2342N  
Cx486S40 DB2343C  
Cx486S40 DB2343K  
Cx486S33 DB2344C  
Cx486S33 DB2344E  
Cx486S40 DB2344E  
Cx486S40 DB2344H  
Cx486S33 DB2345C  
Cx486SLCe-V25MP DF7338D QFP
Cx486SLCe-V25MP DF7339E QFP
Cx486DRx2-20-40MP FF5346A QFP
Cx486DRx2-16-32GP AD2331B  
Cx486DRx2-25-50GP ADA332A  
Cx486DRx2-25-50GP AB3336A Japan
Cx486DRx2-25-50GP ADA3337C Top marked
Cx486DRx2-20-40GP AB3339E Japan
Cx486DRx2-20-40GP AB3341A Japan
Cx486DRx2-25-50GP FL5407C Front
Cx486DRx2-16-32GP FD5411A  
Cx486DRx2-33-66GP F2B6438P Japan
Cx486DRx2-33-66GP F2B6448J Japan
Cx486DX50 ADB346C  
Cx486DX-40 ALB348A USA HS
Cx486DX50 ALC350G  
Cx486DX-40GP ALC350W  
Cx486DX-33GP ALC401B  
Cx486DX-40GP FK3407T Gold bottom IBMish
Cx486DX-40 DBB409D HS Japan
Cx486DX-33GP ALE409N  
Cx486DX-33GP ALE411G  
Cx486DX-33GP FK5412B Gold bottom IBMish
Cx486DX-40GP FK5412P Gold bottom IBMish
Cx486DX-40 FK5413TT  
Cx486DX-40 ABE413Q Japan
Cx486DX-40GP ABE413R Japan
Cx486DX-40 FK5417JJ  
Cx486DX-40 ABF418E Japan HS (M0.6)
Cx486DX-40 ABF419E Japan
Cx486DX-40GP F1K6431D USA
Cx486DX-40 A2BF433B Japan
Cx486DX-40GP F1B6433L  
Cx486DX-33GP D2BH434F Japan
Cx486DX-V33GP FJ5415E QFP
Cx486DX-V33GP FJ5415E QFP
Cx486DX-V33GP FJ5415E  
Cx486DX2-50 FK5414Z  
Cx486DX2-50 FK5417W IBMish
Cx486DX2-50 FK6418Y  
Cx486DX2-50 FK8422A  
Cx486DX2-50 FL9429W  
Cx486DX2-50 FL9430A  
Cx486DX2-50 FL9431V  
Cx486DX2-50 A2LH432B  
Cx486DX2-50 F1L9433C  
Cx486DX2-50 F2KM434Q HS (IMBish markins) writeback
  F2KM435FF writeback
Cx486DX2-50 H1LP507B writeback (M0.7)
CxDX2v50 G1JL438C QFP
Cx486DX2-66 FK9420Q? IBMish (009)
Cx486DX2-66 A3LM434G Writeback
Cx486DX2-66 A3LM434K Writeback
Cx486DX2-66 A3LM441G Writeback
Cx486DX2-66 A3LM441K  
Cx486DX2-66 A3LM442A  
Cx486DX2-66 F2CM442F  
Cx486DX2-66 A3LM442H  
Cx486DX2-66 A3LM445M  
Cx486DX2-66 H1LM448G  
Cx486DX2-66 A3LM448Q  
Cx486DX2-66 A3LM448U  
Cx486DX2-66 A3LP510J  
Cx486DX2-66 A3LP513K  
Cx486DX2-66 A6FR515R  
Cx486DX2-66 H1LP519A  
Cx486DX2-66 H1LP519B  
Cx486DX2-66 H1LP519D  
Cx486DX2-66 A6CR524G  
Cx486DX2-66 A6LT526D  
Cx486DX2-66 A6FT530L  
Cx486DX2v66 G1BN448K 017
Cx486DX2v66 G1KN451U IBMish 3.6/4.0
Cx486DX2v66 G1KQ507C USA 3.45 3.6 4.0
Cx486DX2v66 G1BQ509G 017 3.45v Japan
Cx486DX2v66 G1CQ511D USA 3.45 3.6 4.0
Cx486DX2v66 G1CQ514G USA 3.45 3.6 4.0
Cx486DX2v66 G1FQ515B  
Cx486DX2v66 G4CQ519M 3.45V/3.6V/4.0V
Cx486DX2v66 G3FS521B 3.3 3.45 3.6
Cx486DX2v66 G3CS523J 3.3 3.45 3.6
Cx486DX2-80 A8LP514E  
Cx486DX2-80 A8LP516M  
Cx486DX2-80 A8LP517A  
Cx486DX2-80 A6LT526S  
Cx486DX2-80 A6FT529H  
Cx486DX2-80 A6FT529E USA HS
Cx486DX2-V80 G1KN445Q  
Cx486DX2-V80 G1KQ504B 4.0V
Cx486DX2-V80 G1FQ515F 4.0V
Cx486DX2-V80 G1FQ515F  
  G3CQ517A 017 3.45
Cx486DX2-V80 G4CQ518C 017
Cx486DX2-V80 G3FS525N 034 3.45
Cx486DX2-V80 G3KS525J  
Cx486DX4 100 G3LU528H  
Cx486DX4 100 G3FU529J GP4
Cx486DX4 100 G3FU529J 3.45V GP4
Cx486DX4 100 G3LU531E 3.45
Cx486DX4 100 G3FU531A DX4-P/O 3.45
Cx486DX4 100 G3FU532K DX4-P/O 3.45
5x86-100GP G5L7532L  
5x86-100GP G5F7533A  
5x86-100GP G5F8538AE  
5x86-100GP G5L8538E 026 3.6
5x86-100GP G5F8539E  
5x86-100GP G5F8540C  
5x86-100GP G5F8541G  
5x86-120GP G5K8542B  
5x86-100GP G5F8542D  
5x86-100GP G5L8543D 026 3.6
5x86-100GP G5F8543J  
5x86-100GP 030 G5L8544J  
5x86-100GP 030 G5F8545B  
5x86-100GP G5F9545L  
5x86-120GP 026 G5K9546G  
5x86-100GP G5F9546S 026 3.6V
5x86-100GP G5K8548AK  
5x86-120GP 026 G5FB603C  
5x86-100GP G5F8607G  
DX-40 HB70M4410 H431152 CANADA
DX-40 HB70J4410 H431130 CANADA
DX-40 BB70B4450
DX-50 BD70N501
B7272B USA
DX2-50 BD70M501 B7266 USA
DX2-50 HD70R4221 H416175 USA
HD70V5010 H446344 USA
BD70J448 B6697B USA
HD71Z5180 HH504739
  PB70A6320 P535840
PB70C6060 P534812
P521305 CANADA
ST486DX2-66GS PD70Y5310
P518205 USA
ST486DX2-80GS HB70P5179
ST486DX2-80GS PB70A6120 P534797 CANADA
ST486DX2-80GS HB70B9919E H711432 CANADA
ST486DX2-80GS PB70D6150 P525426T
ST486DX2-80GS PB70I6150 P523349T
  PB70D5290 P520273
  PB70H5370 P523369T
ST468DX4V75HS AB70D9720E J722GZD
ST468DX4V10HS AB70C5500 J541MNN
ST468DX4V10HS AB70E9712E
ST468DX4V10HS AB70A6020
ST468DX4V10HS AB70B5500 J340M1F
  AB70H6050 J543PJL
ST5x86V10HS G5FB601E  
ST5x86V10HS G5FB602P  
ST5x86V10HS G5FB602P  
ST5x86V10HS G5FB603A  

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