Motorola ColdFire MCF5281 - Manual (Page 451)

UART Modules
Freescale Semiconductor 23-31
Figure 23-25. UART Mode Programming Flowchart (Sheet 2 of 5)
CHCHK
CHCHK
Place Channel In
Local Loopback
Mode
Enable
Transmitter Clear
Status Word
TxCHK
Is
Transmitter
Ready?
Y
N
SNDCHR
RxCHK
Send Character
To Transmitter
Has
Character Been
Received?
N
Y
A
Waited
Too Long?
N
N
Waited
Too Long?
Y
Y
Set Transmitter-
Never-ready Flag
Set Receiver-
Never-ready Flag
B
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3