Actually these days even Baskin-Robbins has more, but not 505. But as it says in the title, Atmel have 505 different microcontrollers. That’s a lot. Some are AVR, both 8 bit and 32 bit, and some are various flavors of ARM (all 32 bit) ranging from older parts like the ARM9 to various flavors of Cortex ranging from the M0 (tiny microcontroller with no pipeline or cache) up to A5. Of course the ARM product line goes all the way up to 64-bit Cortex-A57 and so on but they are not in any sense of the word microcontrollers and are really only used in SoCs and not standalone products.
But with 505 choices, how do you pick one. It turns out that Atmel have made it relatively easy for you. They have a microcontroller product finder that allows you to put in your hard constraints and it will narrow down the choices. For example, if you want your microcontroller to have at least 64 Kbytes of flash then there are only 257 out of the 505 that will suit you. For each parameter you can set minimums and maximums (except for the yes/no choices).
The things that you can constrain the selection on are:
- how much flash memory (0 to 2Mbytes)
- pin count (6 to 324)
- operating frequency (1 to 536MHz)
- CPU architecture (pick from 8-bit AVR, 32-bit AVR, ARM 926 and 920, ARM Cortex M0, M3, M4, A5)
- SRAM (30 bytes to 256 Kbytes)
- EEPROM (none to 8 Kbytes)
- Max I/O pins (4 to 160)
- picoPower (yes or no)
- operating voltage (various ranges from 0.7V to 6V)
- operating temperature (various from -20[SUP]o[/SUP]C to 150[SUP]o[/SUP]C)
- number of touch channels (none to 256)
- number of timers (1 to 10)
- watchdog (yes or no)
- 32KHz real time clock (yes or no)
- analog comparators (0 to 8)
- temperature sensor (yes or no)
- ADC resolution (8 to 16 bits)
- ADC channels (2 to 28)
- DAC channels (0 to 4)
- UARTs (0 to 8)
- SPI (1 to 12)
- TWI (aka I[SUP]2[/SUP]C) interface (none to 6)
- USB interface (none, device only, host+OTG, host and device)
- PWM channels (0 to 36)
- Ethernet interfaces (none to 2)
- CAN interfaces (none to 2)
Wow, that is a lot of options. But a couple of dozen choices and you can narrow down your choices to something manageable. The interface looks like this:
Let’s pick a microcontroller. I want an ARM Cortex of some flavor. Already choices are down to 189. I want 32K to 128K of flash (now down to 73 choices). I want it to run at an operating frequency of at least 64 MHz (now down to 10). I want 4K of SRAM (turns out all 10 choices already have that much). I need 4 timers. I am now down to 2 choices:
They are the ATSAM3S1C and the ATSAM3S2C. They are both ARM Cortex-M3s. The first has 64K of flash and the second 128K. I can click on the little PDF icon and get a full datasheet for these microprocessors. If I don’t like the choices and I have some flexibility on specs then obviously I can go back and play with the parameters and get some new options.
Or I can click on the “S” to order samples (you have to already have an account with Atmel to do this).
Or click on the shopping cart to get a list of distributors in various parts of the world where I can actually place an order. It even tells me how many each of them have in stock.
The Atmel Microprocessor Product Finder is here.