本程序使用MSP430F149控制USB芯片PDIUSBD12；USB 芯片的数据端口与 MCU 的P5 端口按一一对应的关系连接，而控制端口与MCU 的IO 连接关系为： P2.0--WR_N，P2.1--RD_N，P2.2--A0，P2.3--CS_N。因为 MSP430 系列单片机没有外部总线接口，所以需要上面的四个 IO 与 P5 口配合模拟数据/地址复用的总线读写时序，从而实现对D12 的操作。-This procedure using the USB chip MSP430F149 control PDIUSBD12　USB chip with the MCU data ports according to the P5 port to connect one-to-one relationship, while the control port and the MCU to connect the IO relations: P2.0 WR_N, P2.1 RD_N, P2. 2 A0, P2.3 CS_N. MSP430 MCU because there is no external bus interface, so it is necessary to the above four IO and P5 mouth with simulation data/address multiplexed bus to read and write timing in order to achieve the operation of the D12.