The Cortex-A7 incorporates all features of the high-performance Cortex-A15 and Cortex-A17 processors, including virtualization support in hardware, NEON™, and 128-bit AMBA®4 AXI bus interface.
                                                                                The STM32MP157A devices also embed a Cortex® -M4 32-bit RISC core operating at up to 209 MHz frequency. Cortex-M4 core features a floating point unit (FPU) single precision which supports Arm® single-precision data-processing instructions and data types. The Cortex® -M4 supports a full set of DSP instructions and a memory protection unit (MPU) which enhances application security.
                                                                                The STM32MP157A devices also embed a 3D graphic processing unit (Vivante® - OpenGL® ES 2.0) running at up to 533 MHz, with performances up to 26 Mtriangle/s, 133 Mpixel/s.
                                                                                The STM32MP157A devices provide an external SDRAM interface supporting external memories up to 8-Gbit density (1 Gbyte), 16 or 32-bit LPDDR2/LPDDR3 or DDR3/DDR3L up to 533 MHz.
                                                                                The STM32MP157A devices incorporate high-speed embedded memories with 708 Kbytes of Internal SRAM (including 256 Kbytes of AXI SYSRAM, 3 banks of 128 Kbytes each of AHB SRAM, 64 Kbytes of AHB SRAM in backup domain and 4 Kbytes of SRAM in backup domain), as well as an extensive range of enhanced I/Os and peripherals connected to APB buses, AHB buses, a 32-bit multi-AHB bus matrix and a 64-bit multi layer AXI interconnect supporting internal and external memories access.
                                                                                All the devices offer two ADCs, two DACs, a low-power RTC, 12 general-purpose 16-bit timers, two PWM timers for motor control, five low-power timers, a true random number generator (RNG). The devices support six digital filters for external sigma delta modulators (DFSDM). They also feature standard and advanced communication interfaces.               

请问在哪里能买到？

https://www.stmcu.org.cn/module/forum/thread-620616-1-1.html
这不是这个帖子里楼主展示的电路板吗？咂又换了个号？