65 Simple UART interface

65 : Simple UART interface

How it works

Each transaction consists of two bytes. First byte - address and r/w bit. Second byte - data to be written (write transaction), or data read from internal registers (read transaction).

How to test

After reset LEDs should show 3 horisontal segments.

Read transaction: first byte is send by host, device will reply with one data byte. List of implemented commands:

  1. Read 15:18 bits of signature: send 0x00, device will reply with 0xDA byte

  2. Read 7:0 bits of signature: send 0x02, device will reply with 0xDE byte

  3. Read internal register: send 0x04, device will reply with 0x00 byte (initial value of internal register is 0)

  4. Read led register: send 0x06, device will reply with 0x49 byte (initial value of led register is 0x49)

  5. Read status of input4-input7: send 0x08, device sill reply with byte containing state of the inputs.

Write transaction: host should send two bytes first - command, second data:

  1. Write to internal register: send 0x05, send byte you want to write

  2. Write to LED register: send 0x07, send byte you want to write to LED register


# Input Output
0 clock segment a
1 reset segment b
2 rx segment c
3 input4 segment d
4 input5 segment e
5 input6 segment f
6 input7 segment g
7 input8 tx