说明：  Toggle P1.0 using software and the TA_0 ISR. Timer_A is configured for up mode, thus the timer overflows when TAR counts to CCR0. In this example, CCR0 is loaded with 1000-1. ACLK = TACLK = INCLK = 32768Hz, MCLK = SMCLK = default DCO ~1.045Mhz