1 - Datasheet says that WREG has 4 r bits for specifying the address. But there are 20 registers. How can I address 20 registers with 4 bits?!
2 - According to Figure. 58, upon starting the chip with START=1 and using internal clock, prior to Reset, DRDY should toggle at 2.048MHz/16384=125Hz, but mine toggles at 1KHz or sometimes 500Hz. Is this a problem ?
3- Before I send a command to ADS1194, the DOUT signal is High and DRDY is toggling at 1KHz, After sending the STOP command, DOUT starts toggling exactly like DRDY! With 1 ms peiod where it's high for ~2us. So the chip doesn't respond to command.