Receiver
MSC8113 Reference Manual, Rev. 0
Freescale Semiconductor
21-11
21.2.1 Character Reception
During a UART reception, the receive shift register shifts a frame in through
URXD
. The SCI data
register is the read-only buffer between the IPBus and the receive shift register. After a complete
frame shifts into the receive shift register, the data portion of the frame (the character) is
transferred to the SCI data register. The receive data register full flag, RDRF, in SCISR is set,
indicating that the received character can be read.
The overrun flag, OR, is set when software fails to read the SCIDR before the receive shift
register receives the next character. If the receive interrupt enable bit (SCICR[RIE]) is also set,
the Receive Data Register Full (RDRF) or the OR flags generate an interrupt request.
Begin an SCI reception as follows:
1.
Configure the SCI:
a. Select the target baud rate and write the appropriate value to the SCI Baud Rate
Register (SCIBR). Note that the baud-rate generator is disabled when the baud rate is
zero. Writing to 5 MSB bits of SCIBR (SBR[12–8]) has no effect without also writing
to 7 LSB of SCIBR (SBR[7–0]).
b. Configure
GPIO27
for UART
URXD
(see Chapter 23, GPIO):
— Set PAR[DD27] and PSOR[SO27] (PAR[DD27] = PSOR[SO27] =1) to connect the
UART
URXD
signal to the external connection.
— Clear PDIR[DR27] (PDIR[DR27] = 0).
c. Write to the SCICR to configure data length, parity, and other configuration bits (LOOPS,
RSRC, M, WAKE, ILT, PE, PT) and enable the transmitter, interrupts, receive, and wake up
as required (TIE, TCIE, RIE, ILIE, TE, RE, RWU, and SBK).If the SBK bit is set, the receiver
wakes up if there are particular conditions on the
URXD
signal according to the WAKE control
bit. Refer to Section 21.2.7, Receiver Wake-Up.
2.
Perform the reception procedure for each character:
a. Poll the RDRF flag by reading the SCISR or responding to the UART interrupt.
b. If the RDRF flag is set, read the data to be received from SCIDR, where the ninth bit is read
from R8 bit in SCIDR if the SCI is in 9-bit data format. Reading RDRF bit at SCISR and then
reading new data from SCIDR clears RDRF flag.
3.
Repeat step 2 for each subsequent reception.
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 ...