Modes of Operation
MSC8113 Reference Manual, Rev. 0
Freescale Semiconductor
21-23
21.4.3 Loop Operation
To help isolate system problems, the Loop mode is sometimes used to check software without
changing the physical connections in the external system. In Loop mode, the transmitter output is
connected to the receiver input internally. The
URXD
signal is disconnected from the external
connection which then becomes available for use as a GPIO signal. Clearing the data direction bit
of
UTXD
disconnects the transmitter output from the external connection.
To enable loop operation, set the SCICR[LOOPS] bit and clear SCICR[RSRC]. Setting the
SCICR[LOOPS] bit disables the path from
URXD
to the external output connection. Clearing the
SCICR[RSRC] bit connects the transmitter output to the receiver input. Both the transmitter and
receiver must be enabled (SCICR[TE] = 1 and SCICR[RE] = 1) for loop operation.
21.4.4 Stop Mode
The UART stops its clock to provide reduced power consumption when the UART_STC bit is set
in the Stop Control Register (see page 19-6). When the UART enters Stop mode, the states of the
UART registers are unaffected. The UART registers cannot be accessed during Stop mode. When
the UART_STC bit is cleared, UART operation resumes. Entering Stop mode during a
transmission or reception results in invalid data. Therefore, disable the receiver and transmitter
(SCICR[TE] = 0, SCICR[RE] = 0) before entering Stop mode.
21.4.5 Receiver Standby Mode
Refer to Section 21.2.7, Receiver Wake-Up.
Figure 21-20. Loop Operation (LOOPS = 1, RSRC = 0)
UTXD
URXD
General-Purpose I/O
Transmitter
Receiver
SCIDDR[1]
GPIO
UART
Summary of Contents for MSC8113
Page 1: ...MSC8113 Reference Manual Tri Core 16 Bit Digital Signal Processor MSC8113RM Rev 0 May 2008 ...
Page 20: ...MSC8113 Reference Manual Rev 0 xx Freescale Semiconductor Contents ...
Page 28: ...MSC8113 Reference Manual Rev 0 xxviii Freescale Semiconductor ...
Page 56: ...MSC8113 Reference Manual Rev 0 1 28 Freescale Semiconductor MSC8113 Overview ...
Page 76: ...MSC8113 Reference Manual Rev 0 2 20 Freescale Semiconductor SC140 Core Overview ...
Page 134: ...MSC8113 Reference Manual Rev 0 4 30 Freescale Semiconductor System Interface Unit SIU ...
Page 168: ...MSC8113 Reference Manual Rev 0 6 18 Freescale Semiconductor Boot Program ...
Page 180: ...MSC8113 Reference Manual Rev 0 7 12 Freescale Semiconductor Clocks ...
Page 260: ...MSC8113 Reference Manual Rev 0 8 80 Freescale Semiconductor Memory Map ...
Page 300: ...MSC8113 Reference Manual Rev 0 9 40 Freescale Semiconductor Extended Core ...
Page 304: ...MSC8113 Reference Manual Rev 0 10 4 Freescale Semiconductor MQBus and M2 Memory ...
Page 308: ...MSC8113 Reference Manual Rev 0 11 4 Freescale Semiconductor SQBus ...
Page 590: ...MSC8113 Reference Manual Rev 0 17 46 Freescale Semiconductor Interrupt Processing ...
Page 614: ...MSC8113 Reference Manual Rev 0 18 24 Freescale Semiconductor Debugging ...
Page 622: ...MSC8113 Reference Manual Rev 0 19 8 Freescale Semiconductor Internal Peripheral Bus IPBus ...
Page 724: ...MSC8113 Reference Manual Rev 0 21 32 Freescale Semiconductor UART ...
Page 920: ...MSC8113 Reference Manual Rev 0 25 150 Freescale Semiconductor Ethernet Controller ...
Page 1171: ...MSC8113 Reference Manual Rev 0 Freescale Semiconductor C 61 EF wait_rts P 01077FFC 9F rts 71 ...
Page 1172: ...MSC8113 Reference Manual Rev 0 C 62 Freescale Semiconductor MSC8113 Boot Code ...
Page 1202: ...MSC8113 Reference Manual Rev 0 Index 30 Freescale Semiconductor Index ...