700时PWM为高电平，200时有方波
寄存器配置如下：
EPwm2Regs.TBPRD = EPWM2_TB; // Set timer period
EPwm2Regs.TBPHS.half.TBPHS = 0x0000; // Phase is 0
EPwm2Regs.TBCTR = 0x0000; // Clear counter
// Setup TBCLK
EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up
EPwm2Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Disable phase loading
EPwm2Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1; // Clock ratio to SYSCLKOUT
EPwm2Regs.TBCTL.bit.CLKDIV = TB_DIV1; // Slow just to observe on the scope
// Setup compare
EPwm2Regs.CMPA.half.CMPA = EPWM2_CM;
// Set actions
EPwm2Regs.AQCTLA.bit.CAU = AQ_SET; // Set PWM2A on Zero
EPwm2Regs.AQCTLA.bit.CAD = AQ_CLEAR;
EPwm2Regs.AQCTLB.bit.CAU = AQ_CLEAR; // Set PWM2A on Zero
EPwm2Regs.AQCTLB.bit.CAD = AQ_SET;
// Active Low complementary PWMs - setup the deadband
EPwm2Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE;
EPwm2Regs.DBCTL.bit.POLSEL = DB_ACTV_LOC;
EPwm2Regs.DBCTL.bit.IN_MODE = DBA_ALL;
EPwm2Regs.DBRED = EPWM2_DB;
EPwm2Regs.DBFED = EPWM2_DB;
EPwm2Regs.ETSEL.bit.SOCASEL = 1; // SOCA 触发条件：TBCTR=0（计数器归零）
EPwm2Regs.ETSEL.bit.SOCAEN = 1; // 使能 SOCA 事件
EPwm2Regs.ETPS.bit.SOCAPRD = 1; // 每 1 次事件触发一次 SOCA
EPwm2Regs.CMPCTL.bit.SHDWAMODE = 1; // CMPA 使用影子寄存器
EPwm2Regs.CMPCTL.bit.LOADAMODE = 1; // 在 CTR=0 时加载影子寄存器（与 SOCA 同步）
