Microprocessors and Math Coprocessors

Microprocessors and Math Coprocessors

80387SX
The 80387SX math coprocessor is matched to the speed of the system microprocessor and operates in the synchronous mode.
The 80387SX math coprocessor is software-compatible with the 80387 math coprocessor.
The coprocessor 'busy' signal can be cleared when it is in the latched state.
(coprocessor 'error' signal active) by writing hex 00 to address hex 00F0.
The coprocessor can be reset by writing hex 00 to address hex 00F1.

80487SX
The 80487SX math coprocessor is matched to the speed of the system microprocessor.
The 80487SX math coprocessor is software-compatible with the 80387DX math coprocessor.
The 80487SX contains a 80486SX and disables the resident 80486SX microprocessor when it is installed.

80386SLC
The 80386SLC microprocessor has a 24-bit address bus and a 16-bit data bus.
It is software-compatible with the 80386SX and 80386DX microprocessors.
The 80386SLC has an internal, two-way set-associative, 8KB cache.
The memory cache is integrated on the microprocessor chip, so the memory cache performs 32-bit transfers to the microprocessor.

80486SX
The 80486SX has a 32-bit address bus and a 32-bit data bus.
It is software-compatible with the 80386SX and 80386DX microprocessors.
The 80486SX has an internal, two-way set-associative, 8KB cache.

80486SX2
The 80486SX2 has a 32-bit address bus and a 32-bit data bus.
It runs at 25MHz (system speed) and 50MHz (microprocessor speed).
It is software-compatible with the 80386SX and 80386DX microprocessors.
The 80486SX2 has an internal, two-way set-associative, 8KB cache.

80486DX
The 80486DX has a 32-bit address bus and a 32-bit data bus.
It is software-compatible with the 80386SX and 80386DX microprocessors.
The 80486DX has an internal, two-way set-associative, 8KB cache and includes the 80487SX math coprocessor.

80486DX2
The 80486DX2 has a 32-bit address bus and a 32-bit data bus.
It runs at 25MHz (system speed) and 50MHz (microprocessor speed) or 33MHz/66MHz
It is software-compatible with the 80386SX and 80386DX microprocessors.
The 80486DX2 has an internal, two-way set-associative, 8KB cache and includes the 80487SX math coprocessor.

80486DX4
The 80486DX4 has a 32-bit address bus and a 32-bit data bus.
It runs at 50MHz (system speed) and 100MHz (microprocessor speed).
It is software-compatible with the 80386SX and 80386DX microprocessors.
The 80486DX4 has an internal, two-way set-associative, 16KB cache and includes the 80487SX math coprocessor.

Pentium®
The Pentium® has a 32-bit address bus and a 64-bit data bus.
It is software-compatible with all previous microprocessors.
The Pentium® has an internal, split data and instruction, 8KB write-trough code cache, 8KB write-back data cache, the total of cache is 16KB.
It includes pipelined math coprocessor functions and superscalar architecture (two execution units).
(90 / 100 MHz have the Clock - 1.5 Processor, the number of transistors used is 3.3 million, the operating Voltage is 3.3 V in the other Pentiums processor 5 V. The power Draw / Heat Dissipation (typical - max.) is 4 to 10 Watt (100 MHz)). The FPU (floating point unit) has been completely redesigned. It incorporates an eight-stage pipeline, which can execute one floating point operation every clock cycle.

Pentium® Pro (P6 - released 1996)
(5.5 million transistors + 15.5 million for 256KB cache or + 31 million transistors for the 512KB version)

Like the Pentium®, the Pentium® Pro has 8KB of cache for instructions and 8KB of cache for data. The Pentium® Pro also has 256 KB or 512 KB of level 2 cache on-chip. The biggest advantage of an integrated level 2 cache is that it operates at the internal speed of the processor (150 MHz or higher).

Pentium® II (Klamath - announced 1997)
The processor (packed in a Single Edge Contact Cartridge) complex (SEC cartridge) is connected to the system board via a single edge connector (Slot 1 connector) instead of the standard multi-pin PGA (pin grid array) packages. The core of the Pentium® II is based on the Pentium® Pro except with two significant changes, the MMX instruction set is added and segment register writes have better performance (16-bit software will run faster than Pentium® Pro). Testing under Win95 show, a 266MHz Pentium® II performs about 50% faster than a 200MHz Pentium® Pro.


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