Can anyone explain MPC8306's uart

[leimao]

In one address 0x4500, It have 3 register. receiver buffer register. transmitter holding registers and Divisor least significant byte register. The 3 register in one address. How could I deal with that? I don't know what register I read or write

[scottwood]

That register is normally the transmitter holding register when you write to it, and the receiver buffer register when you read from it.  When you put the UART into a special mode it becomes the divisor least significant byte register.

Note that this UART is almost identical to a standard 16550 (e.g. as found on PCs), so any examples or tutorials you find for programming a standard UART would be applicable.

[addiyi]

Before reading from that address you should look at UIIR register. Please take a look in 8306 RM at chapter 18.3.1.5. Also, you can take a look in 8306SOM_serial project included in CW ( serial driver is already implemented in CodeWarrior as an example).

Adrian