STM32C0 is a new line of Cortex M0+ Microcontrollers this year. Low-end STM32 chips have been trying to dethrone the 8-bit crowd by offering a 32-bit ARM Cortex M0+ for some time, and I welcome this competition. STM32C0 is cost-optimized with 8-pin to 48-pin form factors, and targeting very low end with 6kB SRAM and 48 MHz clock speed.
SPI, UART, I2C, 4+ MHz XTAL and 32kHz XTAL support, multiple timers for PWM, 12-bit ADC with best case 2.5 Megasamples / second.
Not bad for 61-cents (quantity 1k) at Digikey, ehh?
I think the 8-bitters still seem to have more I/O features, but this is a pretty competitive 32-bit chip on the low end. ST-micro is selling this chip as "entry-level 32-bit", saying that you can keep code-compatibility as you scale up your projects. After all, ARM is ARM, be it a tiny Cortex M0+ or a higher end M33, M4 or M7 chip.
For people hoping to scale designs up and down, adding STM32C0 line chips is probably welcome to the STM32 hobbyists.
I have a couple of STM32F4VE boards that we were planning to run ARMmite on but I've been too busy with my MEGA2560 and GCB project to get around to looking at it.
I dunno why the super-low end $1 uCs interest me so much. Its not like I'm mass producing any design that actually needs to come down this cheap, lol.
But yeah, STM32C0 is in a different league than what Mega2560 or ARMmite. Its just so much cheaper / lower end. I'd say STM32C0 is aiming at a PIC12 or ATTiny replacement, at this $1 price point.