关键词: MCU, SWD协议, 任务, 调试接口

Abstract: Generally,the MCU chips use JTAG as the debugging interface,but JTAG takes up at least 4 pins,while SWD(Serialwire debugger)onlytakesup2 pins,which is suitable for the encapsulatingchips with fewer pins.Since SWDisserial,the data is transmitted one byone at the edge of the clock.Accordingto the traditional programming method,the programs will be redundant and complex,and are difficult to understand and apply when a large number of programming.Through the in-depth study of SWD protocol,the basic operations are written as basic tasks,such as reset,key,idle,and write instructions in the protocol，then the medium-sized tasks are written by calling some basic tasks,and finally the large-scale tasks are written by calling medium-sized tasks.The kernel register and peripheral of the MCU chips are accessed by the debugging interface of SWD,whichwasimplementedbyprogrammingwithlarge tasksinthe simulationenvironmentofCDS/incisiv142.

Key words: MCU, SWD agreement, task, debug interface