Memory and speed — sizing the firmware and the bus
512 KB of Flash is a comfortable fit for a Modbus TCP slave with a web server, or for a multi-axis stepper controller with stored motion profiles. The 132 KB SRAM (organized as 132K x 8) gives you enough buffer space for USB OTG transfers or a CAN message queue without external SRAM. At 120 MHz, the Cortex-M3 executes single-cycle multiply and hardware divide, so you get deterministic interrupt latency — important for closed-loop control loops where jitter matters.
Connectivity and peripherals — what's on the bus
The STM32F205VET6TR includes CAN 2.0B, USB OTG (host/device), multiple SPI and I2C ports, plus UART/USART with IrDA and LIN support. There's also an MMC/SDIO interface for external storage. The 16-channel 12-bit ADC and dual 12-bit DAC cover analog I/O without an external converter. The internal oscillator can run the core, but for CAN or USB you'll want an external crystal for accuracy.