一些缩写

字节	内容	汉语
PGA	programmable gain amplifier	可编程增益放大器;
EEG	electroencephalogram	脑电图
ECG	electrocardiography	心电图

Chip Select (CS)

• The CS pin activates SPI communication.
• low before and during the entire SPI communication period
• When CS is high, the DOUT pin enters a high-impedance state.
• DRDY pin operation and data conversion are independent of CS.
• A master device monitoring the DRDY signal can select the appropriate slave device by pulling the CS pin low.
• After the serial communication is finished, always wait four or more tCLK cycles before taking CS high.

Data Input (DIN)

• DIN的数据在SCLK下降沿传给芯片
• 传入指令时，output shift register的数据会被传出。
• 输出数据时，请保证DIN上的数据是有效的
• 如果要输出数据时，没有要传入的指令，DIN上给NOP指令（别乱传）
• 传入多字节指令时要满足Sending Multi-Byte Commands里的要求

Stand-by Mode

All parts of the circuit are shut down except for the reference section.
There are no SCLK rate restrictions for this command and can be issued at any time.
Do not send any other commands other than the wakeup command after the device enters standby mode.

写寄存器

通过DIN，按照规定的时序（首地址，寄存器数量，要写入的值），发送写寄存器指令。（多字节指令）

字节	内容	详细说明
First command byte	010r rrrr	r rrrr is the starting register address.
Second command byte	000n nnnn	n nnnn is the number of registers to write – 1.（别忘了这个-1哦~）
After the command bytes	register data	(in MSB-first format)

写寄存器

读寄存器

通过DIN，按照规定的时序（首地址，寄存器数量），发送读寄存器指令。（多字节指令）
之后DOUT 会发送所读寄存器的值。

字节	内容	详细说明
First command byte	001r rrrr	r rrrr is the starting register address
Second command byte	000n nnnn	n nnnn is the number of registers to read – 1

读寄存器

When the device is in read data continuous mode, an SDATAC command must be issued before the RREG command.
can be issued.

存疑

1. Figure 45. SPI Bus Data Output
   STAT CH1