Title :
A floating point unit for the 68040
Author :
McCloud, Shawn ; Anderson, Donnie ; DeWitt, Chris ; Hinds, Chris ; Ho, Ying-Wai ; Marquette, Danny ; Quintana, Eric
Author_Institution :
Motorola Inc., Austin, TX, USA
Abstract :
The Motorola 68040 floating point unit (FPU) combines three independent state machines, two data paths, and over 100000 transistors to achieve 8-Mflops peak performance and over 3-Mflops Linpack double-precision performance at the introductory speed of 25 MHz. It is optimized for minimum latency and maximum pipelined performance on frequently used double-precision floating point instructions. The FPU is architecturally divided into three piped stages, the conversion unit (CU), the execution unit (XU), and the normalization unit (NU). The control logic is tested using scan to achieve very high ATPG fault coverage while the data paths are tested using functional patterns
Keywords :
computer architecture; microprocessor chips; pipeline processing; 25 MHz; 3 MFLOPS; 3-Mflops Linpack double-precision performance; 8 MFLOPS; 8-Mflops peak performance; ATPG fault coverage; Motorola 68040; control logic; conversion unit; data paths; double-precision floating point instructions; execution unit; floating point unit; functional patterns; maximum pipelined performance; minimum latency; normalization unit; ANSI standards; Automatic test pattern generation; Computer architecture; Coprocessors; Floating-point arithmetic; Hardware; Logic testing; Pipelines; Read-write memory; Software standards;
Conference_Titel :
Computer Design: VLSI in Computers and Processors, 1990. ICCD '90. Proceedings, 1990 IEEE International Conference on
Conference_Location :
Cambridge, MA
Print_ISBN :
0-8186-2079-X
DOI :
10.1109/ICCD.1990.130198