“The main chip on board is the ‘RP2040’ made by Raspberry Pi (their first in-house microcontroller chip!) and is a dual-core ARM Cortex M0+ processor, with a flexible clock running up to 133MHz.

RP2040 microcontroller chip designed by Raspberry Pi in the United Kingdom
Dual-core ARM Cortex M0+ processor, flexible clock running up to 133 MHz
264kB of SRAM, and 2MB of onboard Flash memory
Castellated module allows soldering directly to carrier boards (non-header version only)
USB 1.1 Host and Device support
Low-power sleep and dormant modes
Drag & drop programming using mass storage over USB
26 multi-function GPIO pins
2×SPI, 2×I2C, 2×UART, 3×12-bit ADC, 16×controllable PWM channels
Real-time clock (RTC)
Temperature sensor
Accelerated floating-point libraries on-chip
8×Programmable IO (PIO) state machines for custom peripheral support
Dimensions: 51mm x 21mm”