Section 28 Serial Communication Interface with FIFO/IrDA Interface (SCIF/IrDA)
Rev. 1.00 Oct. 01, 2007 Page 1155 of 1956
REJ09B0256-0100
28.4.2
Operation in Asynchronous Mode
In asynchronous mode, a character that consists of data with a start bit indicating the start of
communication and a stop bit indicating the end of communication is transmitted or received. In
this mode, serial communication is performed with synchronization achieved character by
character.
Inside the SCIF, the transmitter and receiver are independent units, enabling full-duplex
communication. Both the transmitter and receiver have a 16-stage FIFO buffer structure, so that
data can be read or written during transmission or reception, enabling continuous data
transmission and reception.
Figure 28.5 shows the general format for asynchronous serial communication.
In asynchronous serial communication, the transmission line is usually held in the mark state (high
level). The SCIF monitors the transmission line, and when it goes to the space state (low level),
recognizes a start bit and starts serial communication.
One character in serial communication consists of a start bit (low level), followed by
transmit/receive data (LSB-first; from the lowest bit), a parity bit (high or low level), and finally
stop bits (high level).
In reception in asynchronous mode, the SCIF synchronizes with the fall of the start bit. Receive
data can be latched at the middle of each bit because the SCIF samples data at the eighth clock
which has a frequency of 16 times the bit rate.
LSB
Start
bit
MSB
Idle state
(mark state)
Stop bit
0
Transmit/receive data
D0
D1
D2
D3
D4
D5
D6
D7
0/1
1
1
1
1
Serial
data
Parity
bit
1 bit
1 or 2 bits
7 or 8 bits
1 bit or
none
One unit of transfer data (character or frame)
Figure 28.5 Data Format in Asynchronous Communication
(Example with 8-Bit Data, Parity, and Two Stop Bits)
Summary of Contents for SH7763
Page 2: ...Rev 1 00 Oct 01 2007 Page ii of lxvi ...
Page 122: ...Section 2 Programming Model Rev 1 00 Oct 01 2007 Page 56 of 1956 REJ09B0256 0100 ...
Page 144: ...Section 3 Instruction Set Rev 1 00 Oct 01 2007 Page 78 of 1956 REJ09B0256 0100 ...
Page 170: ...Section 4 Pipelining Rev 1 00 Oct 01 2007 Page 104 of 1956 REJ09B0256 0100 ...
Page 282: ...Section 7 Caches Rev 1 00 Oct 01 2007 Page 216 of 1956 REJ09B0256 0100 ...
Page 378: ...Section 9 Interrupt Controller INTC Rev 1 00 Oct 01 2007 Page 312 of 1956 REJ09B0256 0100 ...
Page 514: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Oct 01 2007 Page 448 of 1956 REJ09B0256 0100 ...
Page 630: ...Section 13 PCI Controller PCIC Rev 1 00 Oct 01 2007 Page 564 of 1956 REJ09B0256 0100 ...
Page 710: ...Section 16 Clock Pulse Generator CPG Rev 1 00 Oct 01 2007 Page 644 of 1956 REJ09B0256 0100 ...
Page 732: ...Section 17 Watchdog Timer and Reset WDT Rev 1 00 Oct 01 2007 Page 666 of 1956 REJ09B0256 0100 ...
Page 752: ...Section 18 Power Down Mode Rev 1 00 Oct 01 2007 Page 686 of 1956 REJ09B0256 0100 ...
Page 772: ...Section 19 Timer Unit TMU Rev 1 00 Oct 01 2007 Page 706 of 1956 REJ09B0256 0100 ...
Page 824: ...Section 21 Compare Match Timer CMT Rev 1 00 Oct 01 2007 Page 758 of 1956 REJ09B0256 0100 ...
Page 1124: ...Section 26 I 2 C Bus Interface IIC Rev 1 00 Oct 01 2007 Page 1058 of 1956 REJ09B0256 0100 ...
Page 1350: ...Section 30 SIM Card Module SIM Rev 1 00 Oct 01 2007 Page 1284 of 1956 REJ09B0256 0100 ...
Page 1484: ...Section 33 Audio Codec Interface HAC Rev 1 00 Oct 01 2007 Page 1418 of 1956 REJ09B0256 0100 ...
Page 1560: ...Section 35 USB Host Controller USBH Rev 1 00 Oct 01 2007 Page 1494 of 1956 REJ09B0256 0100 ...
Page 1720: ...Section 37 LCD Controller LCDC Rev 1 00 Oct 01 2007 Page 1654 of 1956 REJ09B0256 0100 ...
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