I am deeply interested in motor control as you can read in my “about” page. I also currently work with 8-bit MCU (though I’m starting to move to 32-bit technologies as well, as you can read in my blog post below). Even with my interest in motor control, I haven’t done a lot of work with DSPs (shame on me), luckily 8-bit MCU are becoming more and more specialized these days.
Freescale (when it was still Motorola) used to have a really nice MCU called HC08MR, part of the HC08 CPU family, the father of the S08. The HC08MR was an MCU specifically designed for the low-end motor control market, specially BLDC motors and ACIM motor with simple control techniques (V/Hz conversion technique, not fancy stuff like vector control, of which I hope I will eventually talk…when I understand it well enough). The HC08MR has lived a long and happy life, even spawning some curious devices like the MC3PHAC, an analog + MCU + firmware integrated device, basically a plug&play ACIM motor control, very cool indeed.
Now we have the S08 CPU, faster bus clocks and cooler peripherals, so it was only natural that Freescale came out with a new and fresh 8-bit motor control MCU. At last it happened, and last week the S08MP family was launched. The S08MP is a little controller filled with peripherals besides the peripherals you would expect in a current 8-bit microcontroller it has some cool features like: FlexTimer (FTM) module specially designed for motor control with complementary PWM and dead-time insertion (one FTM has 6 channels and a secondary one has 2 channels), 2 programable delay blocks (little timers designed to synchronize two peripherals like the ADC with the timer), programable gain amplifier that can be linked with the ADC, high-speed analog comparators, 5-bit DAC and a CRC generator. All these features help make motor controllers that are both low-cost (1 to 2 dlls at 10,000 pieces, the most expensive ones are automotive certified) and still full of features. Reference designs for both sensorless and sensor BLDC motor controls are expected to be published very soon. Won’t be long before other reference designs come out doing maybe V/Hz conversion for ACIM motors or maybe even steppers. There are also other places where this MCU could shine, like power factor conversion or high brightness LED control (get it? Shine, LED? Ok, a bit lame…get it? Bit? Sorry, I’ll stop now).
In the coming months I’ll be writing more about this fascinating little device. I’ve had it near my heart ever since I first heard of it and now it’s right here in my cubicle happily turning a small motor round and round (pure geek bliss). I’ll probably even post a picture of me and S08MP16 smiling together, or I probably won’t, I wouldn’t want my readers to think I’m a creepy semiconductor freak (though I probably am).