Microprogramming: History and Evolution - Edwardbosworth.com
Microprogramming: History and Evolution - Edwardbosworth.com Microprogramming: History and Evolution - Edwardbosworth.com
The Microprogrammed Control Unit In a microprogrammed control unit, the control signals correspond to bits in a micromemory (CROM for Control ROM), which are read into a micro–MBR. This register is just a set of D flip–flops, the contents of which are emitted as signals. The micro–control unit ( CU ) 1) places an address into the micro–Memory Address Register ( MAR ), 2) the control word is read from the Control Read–Only Memory, 3) puts the microcode word into the micro–Memory Buffer Register, and 4) the control signals are issued.
Maurice Wilkes Maurice Wilkes worked in the Computing Laboratory at Cambridge University beginning in 1936, but mostly from 1945 as he served in WW 2. He read von Neumann’s preliminary report on the EDVAC in 1946. He immediately ―recognized this as the real thing‖ and started on building a stored program computer. In August 1946 he attended a series of lectures ―Theory and Techniques for Design of Electronic Digital Computers‖ given at the Moore School of Engineering at the University of Pennsylvania and met many of the designers of the ENIAC. On May 6, 1949 the EDSAC was first operational, computing the values of N 2 for 1 N 99. In 1951, Wilkes published The Preparation of Programs for Electronic Digital Computers, the first book on programming. I have a 1958 edition. Also in 1951, Wilkes published a paper ―The Best Way to Design an Automatic Calculating Machine‖ that described a technique that he microprogramming. This technique is still in use today and still has the same name. In 1953, Wilkes and Stringer further described the technique and considered issues of design complexity, test and verification of the control logic, pipelining access to the control store, and support of different ISA (Instruction Set Architectures) (Wilkes and Stringer, 1953).
- Page 1 and 2: The Evolution of Microprogramming I
- Page 3 and 4: Design of the Control Unit There ar
- Page 5: How Does the Control Unit Work? The
- Page 9 and 10: A Diode Memory A diode is a one way
- Page 11 and 12: Early Interest in Microprogramming
- Page 13 and 14: Microprogramming is Taken Seriously
- Page 15 and 16: The Microprogram Design Process Her
- Page 17 and 18: Benefits of Microprogramming As not
- Page 19 and 20: Side-Effects of Microprogramming It
- Page 21 and 22: Microprogramming and Memory Technol
- Page 23 and 24: The IA-32 Control Unit In order to
- Page 25: References (Davies, 1972) Readings
Maurice Wilkes<br />
Maurice Wilkes worked in the Computing Laboratory at Cambridge University<br />
beginning in 1936, but mostly from 1945 as he served in WW 2.<br />
He read von Neumann’s preliminary report on the EDVAC in 1946. He immediately<br />
―recognized this as the real thing‖ <strong>and</strong> started on building a stored program <strong>com</strong>puter. In<br />
August 1946 he attended a series of lectures ―Theory <strong>and</strong> Techniques for Design of<br />
Electronic Digital Computers‖ given at the Moore School of Engineering at the<br />
University of Pennsylvania <strong>and</strong> met many of the designers of the ENIAC.<br />
On May 6, 1949 the EDSAC was first operational, <strong>com</strong>puting the values of N 2 for<br />
1 N 99. In 1951, Wilkes published The Preparation of Programs for Electronic<br />
Digital Computers, the first book on programming. I have a 1958 edition.<br />
Also in 1951, Wilkes published a paper ―The Best Way to Design an Automatic<br />
Calculating Machine‖ that described a technique that he microprogramming. This<br />
technique is still in use today <strong>and</strong> still has the same name.<br />
In 1953, Wilkes <strong>and</strong> Stringer further described the technique <strong>and</strong> considered issues of<br />
design <strong>com</strong>plexity, test <strong>and</strong> verification of the control logic, pipelining access to the<br />
control store, <strong>and</strong> support of different ISA (Instruction Set Architectures)<br />
(Wilkes <strong>and</strong> Stringer, 1953).