2006

December 30, 2006

Published by Gary Stringham at December 30, 2006

Categories

Best Practices

Basic Interrupt Behavior

On an ASIC, my ISR had to write a 1 in one place and a 0 in another place to acknowledge (ack) the interrupt. The hardware engineer I talked to tried to explain how one was an interrupt bit so that is why it needed a 1, but the other […]

November 30, 2006

Published by Gary Stringham at November 30, 2006

Categories

Best Practices

Balancing How Firmware Waits on Hardware

A common question engineers often wrestle with is how long hardware will take to do a requested task so firmware can take the next step. Engineers implement different designs (both in hardware and firmware) depending on the length of time, and these designs have varying impacts on hardware and firmware […]

October 31, 2006

Published by Gary Stringham at October 31, 2006

Categories

Best Practices

Different Bit Types in Different Registers

Several years ago I came across a register that, at first glance, seemed to be a typical register with several read/write bits. Upon closer inspection, I saw that one bit behaved differently, depending on its state and whether I was writing a 1 or a 0 to it. Since firmware […]

September 30, 2006

Published by Gary Stringham at September 30, 2006

Categories

Best Practices

Early Hardware/Firmware Collaboration

A few years ago, I was invited to a high-level design review of a new SoC. The proposed design contained an I/O block that needed features added. I successfully convinced them to replace that block instead with an existing block that had the needed features, had seen silicon, and had […]