The STM32F21x family is based on the high-performance ARM Cortex-M3 32-bit RISC core operating at a frequency of up to 120 MHz. The family incorporates high-speed embedded memories (Flash memory up to 1 Mbyte, up to 128 Kbytes of system SRAM), up to 4 Kbytes of backup SRAM, and an extensive range of enhanced I/Os and peripherals connected to two APB buses, three AHB buses and a 32-bit multi-AHB bus matrix.The devices also feature an adaptive real-time memory accelerator (ART Accelerator) which allows to achieve a performance equivalent to 0 wait state program execution from Flash memory at a CPU frequency up to 120 MHz. This performance has been validated using the CoreMark benchmark.All devices offer three 12-bit ADCs, two DACs, a low-power RTC, twelve general-purpose 16-bit timers including two PWM timers for motor control, two general-purpose 32-bit timers. a true number random generator (RNG). They also feature standard and advanced communication interfaces. New advanced peripherals include an SDIO, an enhanced flexible static memory control (FSMC) interface (for devices offered in packages of 100 pins and more), a cryptographic acceleration cell, and a camera interface for CMOS sensors. The devices also feature standard peripherals.
Core: ARM 32-bit Cortex™-M3 CPU (120 MHz max) with Adaptive real-time accelerator (ART Accelerator™ allowing 0-wait state execution performance from Flash memory, MPU, 150 DMIPS/1.25 DMIPS/MHz (Dhrystone 2.1)
Memories
Up to 1 Mbyte of Flash memory
512 bytes of OTP memory
Up to 128 + 4 Kbytes of SRAM
Flexible static memory controller that supports Compact Flash, SRAM, PSRAM, NOR and NAND memories
LCD parallel interface, 8080/6800 modes
Clock, reset and supply management
From 1.8 to 3.6 V application supply+I/Os
POR, PDR, PVD and BOR
4 to 26 MHz crystal oscillator
Internal 16 MHz factory-trimmed RC
32 kHz oscillator for RTC with calibration
Internal 32 kHz RC with calibration
Low power
Sleep, Stop and Standby modes
VBATsupply for RTC, 20 × 32 bit backup registers, and optional 4 KB backup SRAM
3 × 12-bit, 0.5 µs ADCs with up to 24 channels and up to 6 MSPS in triple interleaved mode
2 × 12-bit D/A converters
General-purpose DMA: 16-stream controller with centralized FIFOs and burst support
Up to 17 timers
Up to twelve 16-bit and two 32-bit timers, up to 120 MHz, each with up to 4 IC/OC/PWM or pulse counter and quadrature (incremental) encoder input
Debug mode: Serial wire debug (SWD), JTAG, and Cortex-M3 Embedded Trace Macrocell™
Up to 140 I/O ports with interrupt capability:
Up to 136 fast I/Os up to 60 MHz
Up to 138 5 V-tolerant I/Os
Up to 15 communication interfaces
Up to 3 × I²C interfaces (SMBus/PMBus)
Up to 4 USARTs and 2 UARTs (7.5 Mbit/s, ISO 7816 interface, LIN, IrDA, modem ctrl)
Up to 3 SPIs (30 Mbit/s), 2 with muxed I²S to achieve audio class accuracy via audio PLL or external PLL
2 × CAN interfaces (2.0B Active)
SDIO interface
Advanced connectivity
USB 2.0 full-speed device/host/OTG controller with on-chip PHY
USB 2.0 high-speed/full-speed device/host/OTG controller with dedicated DMA, on-chip full-speed PHY and ULPI
10/100 Ethernet MAC with dedicated DMA: supports IEEE 1588v2 hardware, MII/RMII
8- to 14-bit parallel camera interface (48 Mbyte/s max.)
Cryptographic acceleration
Hardware acceleration for AES 128, 192, 256, Triple DES, HASH (MD5, SHA-1)
Analog true random number generator
CRC calculation unit
96-bit unique ID
