184.108.40.206.1 TC Registers Read Access
TC registers read accesses can be done in two ways:
- A direct read to the TC registers. In this case, there can be a discrepancy between the final time read and the real time because the RTC keeps running because some of the registers can toggle in between register accesses. Software must manage the register change during the reading.
- Read access to shadowed TC registers. These registers are at the same addresses as the normal TC registers. They are selected by setting the GET_TIME bit in the RTC_CTRL_REG register. When this bit is set, the content of all TC registers is transferred into shadow registers so they represent a coherent timestamp, avoiding any possible discrepancy between them. When processing the read accesses to the TC registers, the value of the shadowed TC registers is returned so it is completely transparent in terms of register access.