16.3.3 General Read Synchronization
Read-synchronized registers are synchronized each time the register value is
updated but the corresponding SYNCBUSY bits are not set. Reading a read-synchronized
register does not start a new synchronization, it returns the last synchronized value.
Note: The corresponding bits in
SYNCBUSY will automatically be set when the device wakes up from sleep because
read-synchronized registers need to be synchronized. Therefore reading a
read-synchronized register before its corresponding SYNCBUSY bit is cleared will
return the last synchronized value before sleep mode.