MicroVAX 78032
Encyclopedia
The MicroVAX 78032 is a microprocessor
developed and fabricated by Digital Equipment Corporation
(DEC) that implemented a subset of the VAX
instruction set architecture (ISA). The 78032 was used exclusively in DEC's VAX
-based systems, starting with the MicroVAX II
in 1985. When clocked at a frequency of 5 MHz, the 78032's integer performance is comparable to the VAX-11/780
superminicomputer, which was introduced on 25 October 1977. The microprocessor could be paired with the MicroVAX 78132 floating point accelerator for improved floating point performance.
The 78032 represented a number of firsts for DEC. It was DEC's first single-chip microprocessor implementation of the VAX ISA and DEC's first self-fabricated microprocessor. The MicroVAX 78032 is also notable as it was the first semiconductor device to be registered for protection under the Semiconductor Chip Protection Act of 1984
.
The MicroVAX 78032 contains 125,000 transistors on a 8.7 by 8.6 mm (74.82 mm2) die
that was fabricated in DEC's ZMOS process, a 3.0 µm NMOS logic
process with two layers of aluminum interconnect. The die is packaged in a 68-pin surface-mounted leaded chip carrier
.
for the MicroVAX 78032 microprocessor. It interfaces to the MicroVAX 78032 via the DAL bus and a few control lines. The MicroVAX 78132 was responsible for executing 61 out of 70 floating-point instructions defined by the MicroVAX subset of the VAX ISA and accelerates nine integer instructions.
The MicroVAX 78132 has a 100 ns microcycle divided into four 25 ns clock phases which is generated by a 40 MHz input clock. It was composed of five "elements": a 67-bit fraction processor, a 13-bit exponent processor, a 1-bit sign processor, a microsequencer and a bus interface unit.
The MicroVAX 78132 contained 32,141 transistors on a die measuring 8.4 mm by 6.6 mm (55.44 mm2). It was fabricated in DEC's ZMOS process, a 3.0 µm NMOS process with two layers of aluminum interconnect; and is packaged in a 68-pin surface-mounted leaded chip carrier.
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
developed and fabricated by Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
(DEC) that implemented a subset of the VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
instruction set architecture (ISA). The 78032 was used exclusively in DEC's VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
-based systems, starting with the MicroVAX II
MicroVAX
The MicroVAX was a family of low-end minicomputers developed and manufactured by Digital Equipment Corporation . The first model, the MicroVAX I, was introduced in 1984...
in 1985. When clocked at a frequency of 5 MHz, the 78032's integer performance is comparable to the VAX-11/780
VAX-11
The VAX-11 was a family of minicomputers developed and manufactured by Digital Equipment Corporation using processors implementing the VAX instruction set architecture . The VAX-11/780 was the first VAX computer.- VAX-11/780 :...
superminicomputer, which was introduced on 25 October 1977. The microprocessor could be paired with the MicroVAX 78132 floating point accelerator for improved floating point performance.
The 78032 represented a number of firsts for DEC. It was DEC's first single-chip microprocessor implementation of the VAX ISA and DEC's first self-fabricated microprocessor. The MicroVAX 78032 is also notable as it was the first semiconductor device to be registered for protection under the Semiconductor Chip Protection Act of 1984
Semiconductor Chip Protection Act of 1984
The Semiconductor Chip Protection Act of 1984 is an act of the US Congress that makes the layouts of integrated circuits legally protected upon registration, and hence illegal to copy without permission.-Background:...
.
The MicroVAX 78032 contains 125,000 transistors on a 8.7 by 8.6 mm (74.82 mm2) die
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
that was fabricated in DEC's ZMOS process, a 3.0 µm NMOS logic
NMOS logic
N-type metal-oxide-semiconductor logic uses n-type metal-oxide-semiconductor field effect transistors to implement logic gates and other digital circuits...
process with two layers of aluminum interconnect. The die is packaged in a 68-pin surface-mounted leaded chip carrier
Chip carrier
A chip carrier, also known as a chip container or chip package, is a container for a transistor or an integrated circuit. The carrier usually provides metal leads, or "pins", which are sturdy enough to electrically and mechanically connect the fragile chip to a circuit board. This connection may be...
.
MicroVAX 78132
The MicroVAX 78132 (otherwise known as the DC337) is a floating-point coprocessorCoprocessor
A coprocessor is a computer processor used to supplement the functions of the primary processor . Operations performed by the coprocessor may be floating point arithmetic, graphics, signal processing, string processing, or encryption. By offloading processor-intensive tasks from the main processor,...
for the MicroVAX 78032 microprocessor. It interfaces to the MicroVAX 78032 via the DAL bus and a few control lines. The MicroVAX 78132 was responsible for executing 61 out of 70 floating-point instructions defined by the MicroVAX subset of the VAX ISA and accelerates nine integer instructions.
The MicroVAX 78132 has a 100 ns microcycle divided into four 25 ns clock phases which is generated by a 40 MHz input clock. It was composed of five "elements": a 67-bit fraction processor, a 13-bit exponent processor, a 1-bit sign processor, a microsequencer and a bus interface unit.
The MicroVAX 78132 contained 32,141 transistors on a die measuring 8.4 mm by 6.6 mm (55.44 mm2). It was fabricated in DEC's ZMOS process, a 3.0 µm NMOS process with two layers of aluminum interconnect; and is packaged in a 68-pin surface-mounted leaded chip carrier.
Further reading
- Wolrich, G. et al. (October 1984). "A high performance floating point coprocessor". IEEE Journal of Solid-State Circuits 19 (5): pp. 690–696.