Texas Instruments TMS570LC4357 - Page 1938

Application of the ECAP Module www.ti.com
1938
SPNU563A–March 2018
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Enhanced Capture (eCAP) Module
33.3.1.1 Code Snippet for CAP Mode Absolute Time, Rising Edge Trigger
// Code snippet for CAP mode Absolute Time, Rising edge trigger
// Initialization Time
//=======================
// ECAP module 1 config
ECap1Regs.ECCTL1.bit.CAP1POL = EC_RISING;
ECap1Regs.ECCTL1.bit.CAP2POL = EC_RISING;
ECap1Regs.ECCTL1.bit.CAP3POL = EC_RISING;
ECap1Regs.ECCTL1.bit.CAP4POL = EC_RISING;
ECap1Regs.ECCTL1.bit.CTRRST1 = EC_ABS_MODE;
ECap1Regs.ECCTL1.bit.CTRRST2 = EC_ABS_MODE;
ECap1Regs.ECCTL1.bit.CTRRST3 = EC_ABS_MODE;
ECap1Regs.ECCTL1.bit.CTRRST4 = EC_ABS_MODE;
ECap1Regs.ECCTL1.bit.CAPLDEN = EC_ENABLE;
ECap1Regs.ECCTL1.bit.PRESCALE = EC_DIV1;
ECap1Regs.ECCTL2.bit.CAP_APWM = EC_CAP_MODE;
ECap1Regs.ECCTL2.bit.CONT_ONESHT = EC_CONTINUOUS;
ECap1Regs.ECCTL2.bit.SYNCO_SEL = EC_SYNCO_DIS;
ECap1Regs.ECCTL2.bit.SYNCI_EN = EC_DISABLE;
ECap1Regs.ECCTL2.bit.TSCTRSTOP = EC_RUN; // Allow TSCTR to run
// Run Time ( e.g. CEVT4 triggered ISR call)
//==========================================
TSt1 = ECap1Regs.CAP1; // Fetch Time-Stamp captured at t1
TSt2 = ECap1Regs.CAP2; // Fetch Time-Stamp captured at t2
TSt3 = ECap1Regs.CAP3; // Fetch Time-Stamp captured at t3
TSt4 = ECap1Regs.CAP4; // Fetch Time-Stamp captured at t4
Period1 = TSt2-TSt1; // Calculate 1st period
Period2 = TSt3-TSt2; // Calculate 2nd period
Period3 = TSt4-TSt3; // Calculate 3rd period