AMD Am386
Am386DX-40
Developer	AMD
Manufacturer	AMD
Type	Microprocessors
Introduction	1989 (announced) March, 1991 (launch)
Production	1990
Architecture	80386
ISA	IA-32
Word size	32 bit 4 octets 8 nibbles
Process	800 nm 0.8 μm 8.0e-4 mm
Technology	CMOS
Clock	20 MHz-40 MHz
Package	PGA-132, PQFP-132, PGA-88, PQFP-100
Succession
←	→
Am286	Am486

Am386 was a family of 32-bit 3rd-generation x86 microprocessors introduced by AMD in 1991. Am386 chips were 100%-compatible with Intel's 80386, had better performance, ran cooler, used less power, and introduced a number of new innovative features such as sleep-mode for laptops. This family became a major success for AMD, allowing them become a fully fledged proprietary x86 microprocessor designer, as opposed to just a second source manufacturer.

History

In 1985 Intel introduced its 3rd generation x86 microprocessors, the 80386 family. AMD had a cross-licensing agreement with Intel which began in 1976, extended in 1982, but was terminated in 1987 - an agreement that AMD used to second-source Intel's 8086, 80186, and 80286. AMD's argument was that the 82 contract covered all derivatives of those chips while Intel claimed the contract only covered the 80286 family and prior. While Intel refused to share their microcode for the 386, AMD used that agreement to obtain it anyway through reverse engineering. AMD started reverse engineering the chip in 1988. The team responsible for the project was headed by Ben Oliver's group in their new their 0.8 µm process in Austin, TX. Development took around eighteen months with a working batch by the end of 1989. Expensive and lengthy litigation with Intel delayed their introduction to the market until March of 1991 which nullified Intel's attempt at trademarking the generic "386" chip designation.

The final result was a chip that had better over 20% better performance, ran cooler, and used less power. AMD started shipping 386 chips in March of 1991. Regardless of the delay, 386 was a major success for AMD ending up selling millions of Am386 chips, emerging as a serious contender to Intel. By the end of 1992, AMD was out-producing Intel with 9.5 million units sold, generating over half a billion dollars, and overtaking Motorola as the world's second largest microprocessor manufacturer. That year AMD was accounted for around 60% of all 386s sold.

Members

Part	Ext. Bus	Frequency
Am386DX/DXL-20	32-bit	20 MHz
Am386SX/SXL-20	16-bit	20 MHz
Am386DX/DXL-25	32-bit	25 MHz
Am386SX/SXL-25	16-bit	25 MHz
Am386DX/DXL-33	32-bit	33 MHz
Am386SX/SXL-33	16-bit	33 MHz
Am386DX/DXL-40	32-bit	40 MHz
Am386DX-40	32-bit	40 MHz
Am386SX-40	16-bit	40 MHz
Am386SE-25KC	32-bit	25 MHz

See also

• 80386