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Sir Clive Sinclair inspired me and 'whole load of others' at Arm, says CEO Simon Segars

But of course chief exec's first computer was an Acorn

Like so many of us in tech, Arm CEO Simon Segars has his own computing origins story, which he shared during a speech on Tuesday at the Arm DevSummit developer conference.

British-born Segars' interest in computing started at age 14, when he'd go to a shop that had a Sinclair ZX81 computer on display, on which he wrote simple programs, learning about concepts like variables and loops.

"It was expensive at £70, we weren't about to buy one … and [it was] primitive by today's standards. It had a 3MHz, 8-bit microprocessor and a whole 1KB of memory," Segars said.

He paid tribute to Sir Clive Sinclair, who launched the ZX81 in 1981 and died in September this year.

"I want to take a moment to thank him for inspiring me, and a whole load of other Arm people who are roughly my age, with a desire to know more about how computers worked and how to code," Segars said.

In the tinkering, Segars found his interest to be more on the hardware side. He tried to build basic circuits following designs in magazines, and that gave rise into building low-power circuitry.

"I didn't have a power supply so anything I built needed to run off a battery. There was another shop in my hometown, where I would buy individual transistors, resistors and capacitors, then try to build things that can be powered off a pair of AA cells. Just making some LEDs flash was success," Segars continued.

Simon Segars

Out of lousy keyboards might things grow ... Simon Segars in his keynote. Source: Arm. Click to enlarge

Segars finally got his own computer, funnily enough the BBC Micro made by Sinclair's arch-rival Acorn, which was also the birthplace of Arm. He expanded his programming capabilities and was able to see the interaction of hardware and software. He hooked up the computer to external circuits through its expansion port.

"Now I could make the LED flash with a program, and I thought that was really cool. But I wanted to learn more. And I knew I'd only get so far reading magazines and experimenting at home," Segars said.

Going to greater things

After getting a degree in electronic engineering from the University of Sussex in England, he eventually joined Advanced RISC Machines (ARM, now just Arm) in 1991 – a joint-venture created by Acorn, Apple, and VLSI Technology the year before – and led the team that developed the ARM7TDMI CPU.

"Many of you know it as the processor that would unshackle compute from desktops and mainframes, but it also served a very important purpose for our own developer ecosystem," Segars said.

By that, he meant the ARM7TDMI included circuitry that aided greatly in the debugging and testing of low-level code on a processor core sitting inside a complex system on chip.

Specifically, Arm provided a JTAG-style serial interface through which the internal state of the CPU could be inspected: registers could be viewed, instructions inserted into the pipeline, and so on. This debug mode could be activated via breakpoints, watchpoints, or external signals, and was typically used via software running on a connected computer.

"With our investment in the debug tools to utilize this hardware, we enabled software engineers to perform actions that today we take for granted," Segars said.

"These techniques and workflows have become standard practice today, but they were born out of a necessity, brought about by the advancement in semiconductor technology that enabled a processor to become the building block of a bigger chip."


More than 10 billion ARM7TDMI-powered processors have shipped since, with many going into 1990s embedded and mobile devices, including cellphones and PDAs. Notably, the ARM7TDMI marked Nokia's move into 32-bit Arm chips with the 6110. The CPU core also powered Nintendo's GameBoy Advance and was included in the followup Nintendo DS. Segars said Arm's partners have shipped 200 billion Arm-compatible chips in the past 30 years.

Segars in his speech went on to pitch Armv9, its latest architecture, introduced officially in March, saying it was "engineered to power the next decade of computer." The company has said Armv9 will be the base for about 300 billion Arm chips.

Armv9 succeeds Armv8, which was introduced in 2011. The design has a core for artificial intelligence applications and hardware-based sandboxing to isolate and secure code. The architecture will be used in chips for communications, PCs, servers, mobile devices, and embedded applications such as drones, robots and other appliances.

Nvidia's plan to acquire Arm from Softbank as part of a $40 billion deal is facing immense scrutiny.

Ahead of the conference, Arm introduced a product portfolio called Arm Total Solutions for IoT, which includes virtual models of chip being made available in the cloud for developers to write and test code.

Arm on Tuesday also announced a partnership with Tech Mahindra to open the Arm 5G Solutions Lab, where developers will get access to hardware to test applications. Other lab partners include Google, Nvidia and NXP. ®

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