STM32F103C8T6，keil MDK472 SWD下载模式或调试总是出现Error: Flash Download failed - “Cortex-M3“解决

ARM 32-bit Cortex-M3 Microcontroller, 72MHz, 64kB Flash, 20kB SRAM,
PLL, Embedded Internal RC 8MHz and 32kHz, Real-Time Clock,
Nested Interrupt Controller, Power Saving Modes, JTAG and SWD,
3 Synch. 16-bit Timers with Input Capture, Output Compare and PWM,
16-bit 6-ch Advanced Timer, 2 16-bit Watchdog Timers, SysTick Timer,
2 SPI, 2 I2C, 3 USART, USB 2.0 Full Speed Interface, CAN 2.0B Active,
2 12-bit 10-ch A/D Converter,  Fast I/O Ports

这里点Add,没有64K 

解决：先长按复位点下载，会报错，再松开复位，点下载就会下载成功。调试也一样。

SWD下载接线

需要接线：

• VDD
• TMS/SWDIO对应stm32的PA13  
• TCK/SWCLK对应stm32的PA14
• 任意地脚
• RESET对应stm32的NRST 可接可不接