Peripheral set — one chip for gateway and HMI duty
The connectivity list reads like a system-on-chip: Ethernet, CAN, USB, I²C, SPI, UART, and an external bus interface (EBI/EMI). That means a single R7FA6M3AH3CBG#AC0 can act as the Modbus TCP gateway, the HMI controller driving a TFT display via the built-in LCD controller, and the data logger talking to an SD card — all on one 176-LQFP package. The 133 I/O lines leave room for sensor arrays and keypads.
On-chip data conversion and timing
Twenty-four 12-bit SAR ADC channels and two 12-bit DACs cover analog front-end needs — current sensing, potentiometer inputs, or analog output for a servo drive. The internal oscillator saves a crystal if the timing budget allows, and the DMA engine keeps the CPU free for protocol stacks.
What the 120 MHz and 2 MB Flash mean for your BOM
The 120 MHz Cortex-M4F with single-precision FPU handles FFT, filter math, and control loops in software rather than requiring a separate DSP. The 2 MB Flash is sized for a full embedded GUI library (e.g., emWin or LVGL) plus the application firmware, with room left for a bootloader and OTA update staging area. The 640 KB RAM is the headroom that keeps you from adding an external SRAM — a cost and board-area saving.