UART Modules
MCF5253 Reference Manual, Rev. 1
Freescale Semiconductor
15-29
15.4.17 Programming
shows the basic interface software flowchart required for operation of the UART module.
The routines are divided into these three categories:
1. UART Module Initialization
2. I/O Driver
3. Interrupt Handling
15.4.17.1 UART Module Initialization
The UART module initialization routines consist of SINIT and CHCHK. SINIT is called at system
initialization time to check UART operation. Before SINIT is called, the calling routine allocates two
words on the system stack. On return to the calling routine, SINIT passes information on the system stack
to reflect the status of the UART. If SINIT finds no errors, the receiver and transmitter are enabled. The
CHCHK routine performs the actual checks as called from the SINIT routine. When called, SINIT places
the UART in the local loopback mode and checks for the following errors:
•
Transmitter Never Ready
•
Receiver Never Ready
•
Parity Error
•
Incorrect Character Received
15.4.17.2 I/O Driver Example
The I/O driver routines consist of INCH and OUTCH. INCH is the terminal input character routine and
obtains a character from the receiver. OUTCH sends a character to the transmitter.
15.4.17.3 Interrupt Handling
The interrupt-handling routine consists of SIRQ, which is executed after the UART module generates an
interrupt caused by a change in break (beginning of a break). SIRQ then clears the interrupt source, waits
for the next change-in-break interrupt (end of break), clears the interrupt source again, then returns from
exception processing to the system monitor.
Address MBAR + $1FC (UOP00)
MBAR + $23C (UOP01)
MBAR2 + $C3C (UOP02)
Access: User write only
7
6
5
4
3
2
1
0
R
W
RTS
Reset
–
–
–
–
–
–
–
–
Figure 15-22. Output Port Data Registers (UOP0n)
Summary of Contents for MCF5253
Page 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Page 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
Page 32: ...MCF5253 Reference Manual Rev 1 xxxii Freescale Semiconductor...
Page 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Page 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Page 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Page 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Page 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Page 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Page 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Page 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Page 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Page 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Page 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...
