Professional words
- PLL: phase−locked loop (锁相环)
- OTPM: OTP(One Time Programmable)MCU的一种存储器类型，意即一次性编程。多是采用融丝结构，编程过程是不可逆的破坏活动。
- wafer & die & chip
Schematic diagrams
- MSB（Most Significant Bit），最高有效位。
- LSB（Least Significant Bit），最低有效位。
Protocol
The bus is idle when both SCLK and SDATA are HIGH.
Start Condition
A start condition is defined as a HIGH−to−LOW transition on SDATA while SCLK is HIGH.
Stop Condition
A stop condition is defined as a LOW−to−HIGH transition on SDATA while SCLK is HIGH.
Slave Address/Data Direction Byte
Bits [7:1] of this byte represent the device slave address and bit [0] indicates the data transfer direction. A “0” in bit [0] indicates a WRITE, and a “1” indicates a READ.
Function Circuits
Slave Address/Data Direction Byte
A “0” in bit [0] indicates a WRITE, and a “1” indicates a READ. The default slave addresses used by the AR0820AT are 0x20 (write address) and 0x21 (read address) in accordance with the specification.
RESET PULL-UP
Asynchronous reset (active LOW) all settings are restored to factory default
Amazing method of pin connection
Power supply could be on other boards.