Re:In the future even your RAM will have firmware; and the s...
by ohazi on Friday February 05, 2021 @03:11AM
(#26034162)
Amusingly, things sort of went the other way in microcontroller land.
You had SPI, which has a clock and data pin. That got faster and faster. Then there was QSPI (quad SPI) with four data pins, so you could shovel more data per clock, e.g. when loading an initial FPGA configuration, or when a fast CPU wanted to XIP from external flash.
Now apparently there's Octal SPI? Which is... arguably a parallel bus!
Re:In the future even your RAM will have firmware; and the s...
by jleahy on Friday February 05, 2021 @08:29AM
(#26036063)
Sure, but SPI is basically a parallel bus that's 1-bit wide. It has all the hallmarks (separate clock and single-ended signaling), so adding extra bits was an easy thing.
You had SPI, which has a clock and data pin. That got faster and faster. Then there was QSPI (quad SPI) with four data pins, so you could shovel more data per clock, e.g. when loading an initial FPGA configuration, or when a fast CPU wanted to XIP from external flash.
Now apparently there's Octal SPI? Which is... arguably a parallel bus!