SparkFun Forums

[dchrislee]

Hi everyone,

have anyone use UART protocol using 3 wires: TX,RX and REQ (clock)?

May be anyone knows how to make a friendship with AtMega32u4 using that protocol?
If anyone interested what MCU uses it: UPD78054GC.
Is it possible to connect to AVR mcu using MAX232? Thanks!

[n1ist]

Here's a data sheet for the chip. Looks like REQ can be either a baud rate output or input. Based on the schematic, it is being used as an output. I'd try checking if TXD/RXD are standard ASYNC serial; you won't hurt anything by trying.
Probing REQ may give a hint for the baud rate.

/mike

[Valen]

[Deleted] Didn't look into the datasheet. REQ is ASCK, or Asynchronous serial clock. Not some sort of "request" flow-control signal. My bad.