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Structured hardware design, is a modular digital hardware design methodology (for Computer hardware and other hardware) originated by Reiner Hartenstein, who also called it Structured LSI design. This methodology has been introduced by the hardware description language KARL and its interactive graphic companion language ABL, the first language also featuring topological primitives supporting regularly layouted floor planning, avoiding spaghetti-structured wiring patterns to save microchip area and featuring structured wiring functions (shift, shuffle, butterfly, reflect, etc.), so that the language can be used as a design calculus. This is obtained by repetitive arrangement of rectangular macro blocks which can be interconnected using wiring by abutment. An example is partitioning the layout of an adder into a row of equal bit slices cells. In complex designs this structuring may be achieved by hierarchical nesting. The term "tructured hardware design" has been coined by Reiner Hartenstein, reminding to Edsgar Dijkstras structured programming approach by procedure nesting to avoid the disadvantages of go to commands. In this context Hartenstein has also shown, that the bus is as harmful for Structured hardware design, as the go to is for structured programming. Because of the memory wall this harmfulness of the bus is one of the reasons of the von Neumann syndrome.

Based on structured hardware design as a calculus Reiner Hartenstein has proposed in the early 1980ies the use of Term Rewriting for the automatic derival of structured VLSI layout floorplans from a Mathematical formula sources. Two decades later this proposal has been implemented by Mauricio Ayala-Rincon, encouraged by Hartensteins early . So far Rewriting methods had been only used in a bottom-up manner, as i. e. for verification. But by his idea, illustrated by his early integer multiplier example, Hartenstein has been the initiator of using Term Rewriting in a top-down manner for synthesis.

• R. Hartenstein: Structured Hardware Design: a Design Language Approach; North Holland / American Elsevier, Amsterdam / New York, 1977
• E. Dijkstra: Go To Statement Considered Harmful; Communications of the ACM, Vol. 11 (1968)
• R. Hartenstein, G. Koch: The Universal Bus Considered Harmful; Proc. EUROMICRO 1975, Nice France, 2007. (Hrsg. R. Hartenstein, R. Zaks): Microarchitecture of Computer Systems; North Holland /American Elsevier, Amsterdam/New York 1975
• R. Hartenstein: Microprogramming concepts - a step towards structured hardware design; Proc. 7th annual workshop on Microprogramming, Palo Alto, CA, USA,: 1974