LED Drive Control Special Circuit TM1637 Display register address Stored data in the register is transferred to the TM1637 from outside elements by serial interface, with 6 bytes units of address from C0H to C5H in correspondence with the LED lights connected with SEG pin and GRID pin on the chip.LED data is displayed from low level to high level in respect of display address, and should be operated from low level to high level in respect of data bytes. SESESESESESESESEGGGGGGGG12345678 xxHL(low four bits) xxHU(high four bits) B0 B1 B2 B3 B4 B5 B6 B7 C0HL C0HU GRID1 C1HL C1HU GRID2 C2HL C2HU GRID3 C3HL C3HU GRID4 C4HL C4HU GRID5 C5HL C5HU GRID6Interface interpretation Microprocessor data realize the communication with TM1637 by means of two–wire bus interface (Note: The communication method is not equal to 12C bus protocol totally because there is no slave address). When data is input, DIO signal should not change for high level CLK and DIO signal should change for low level CLK signal. When CLK is a high level and DIO changes from high to low level, data input starts. When CLK is a high level and DIO changes from low level to high level, data input ends. TM1637 data transfer carries with answering signal ACK. For a right data transfer, an answering signal ACK is generated inside the chip to lower the DIO pin at the failing edge of the 8th clock. DIO interface wire is released at the end of the 9th clock. 1 、 Command data transfer is as follows (Reading Key Data Timing) 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 CLK DIO command STAR S0 S1 S2 K1 K2 END The chip is The chip is automatically automatically lowered at ACK lowered at ACK low level low level Command: command to read the keys; Key information coding consists of S0, S1, S2, K1 and K2. SGn coding consists of S0, S1, and S2. K1 and K2 are coding for K1 key and K2 key. The key should be read from low level to high level and the clock frequency should be less than 250K.