Motorola MPC823e Reference Manual page 681

16.9.15.18 SCCx UART EVENT REGISTER.When a serial communication controller is in
UART mode, the 16-bit memory-mapped SCCx event register is referred to as the SCCx
UART event register (SCCE–UART). Since each protocol has specific requirements, the
SCCE bits are different for each implementation. This register is used to report events
recognized by the UART channel and to generate interrupts. When an event is recognized,
the SCCx UART controller sets the corresponding bit in the UART event register. Interrupts
generated by this register can be masked in the SCCM–UART register. An example of
interrupts that can be generated by the SCCx UART controller is illustrated in Figure 16-77.
CHARACTERS
RECEIVED BY UART
TIME
LINE IDLE
RXDx
CDx
UART SCCE
EVENTS
CDx
NOTES:
1. The first receive event assumes receive buffers are 6 bytes each.
2. The second IDL event occurs after an all-ones character is received.
3. The second RX event position is programmable based on the MAX_IDL value.
4. The BRKs event occurs after the first break character is received.
5. The CDx event must be programmed in the port C parallel I/O, not in the SCC itself.
LEGEND:
A receive control character defined not to be stored in the receive buffer.
CHARACTERS
TRANSMITTED BY UART
TXDx
RTSx
CTSx
UART SCCE
EVENTS
NOTES:
1. TX event assumes all seven characters were put into a single buffer and CR is set to 1 in the TX buffer descriptor.
2. The CTSx event must be programmed in the port C parallel I/O, not in the SCC itself.
Figure 16-77. SCCx UART Interrupt Event Example
MOTOROLA
10 CHARACTERS
IDL RX
7 CHARACTERS
LINE IDLE
CTSx
MPC823e REFERENCE MANUAL
Communication Processor Module
LINE IDLE
CCR IDL RX IDL BRKs
LINE IDLE
TX CTSx
BREAK
BRKe IDL CDx
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