21. Serial Communication Interface with FIFO (SCIF)
Rev.1.00 Jan. 10, 2008 Page 1097 of 1658
REJ09B0261-0100
(4)
Sending a Break Signal
The input/output condition and level of the SCIF_TXD pin are determined by bits SPB2IO and
SPB2DT in SCSPTR. This feature can be used to send a break signal.
After the serial transmitter is initialized and until the TE bit is set to 1 (enabling transmission), the
SCIF_TXD pin function is not selected and the value of the SPB2DT bit substitutes for the mark
state. The SPB2IO and SPB2DT bits should therefore be set to 1 (designating output and high
level) in the beginning.
To send a break signal during serial transmission, clear the SPB2DT bit to 0 (designating low
level), and then clear the TE bit to 0 (halting transmission). When the TE bit is cleared to 0, the
transmitter is initialized, regardless of the current transmission state, and 0 is output from the
SCIF_TXD pin.
(5)
Receive Data Sampling Timing and Receive Margin in Asynchronous Mode
In asynchronous mode, the SCIF operates on a base clock with frequency of 16 times the bit rate.
In reception, the SCIF synchronizes internally with the fall of the start bit, which it samples on the
base clock. Receive data is latched at the rising edge of the eighth base clock pulse.
Figure 21.22 shows the timing.
0 1 2
3 4
5 6 7 8 9 10 11 12 13 14 15 0 1 2
3 4
5 6 7 8 9 10 11 12 13 14 15 0 1 2
3 4
5
16 clocks
8 clocks
-7.5 clocks
Start bit
+7.5 clocks
D0
D1
Receive data
(SCIF_RXD)
Synchronization
samplin
g
timin
g
Data samplin
g
timin
g
Base clock
Figure 21.22 Receive Data Sampling Timing in Asynchronous Mode
Содержание SH7781
Страница 4: ...Rev 1 00 Jan 10 2008 Page iv of xxx REJ09B0261 0100 ...
Страница 74: ...2 Programming Model Rev 1 00 Jan 10 2008 Page 44 of 1658 REJ09B0261 0100 ...
Страница 272: ...8 Caches Rev 1 00 Jan 10 2008 Page 242 of 1658 REJ09B0261 0100 ...
Страница 376: ...10 Interrupt Controller INTC Rev 1 00 Jan 10 2008 Page 346 of 1658 REJ09B0261 0100 ...
Страница 694: ...13 PCI Controller PCIC Rev 1 00 Jan 10 2008 Page 664 of 1658 REJ09B0261 0100 ...
Страница 762: ...14 Direct Memory Access Controller DMAC Rev 1 00 Jan 10 2008 Page 732 of 1658 REJ09B0261 0100 ...
Страница 788: ...15 Clock Pulse Generator CPG Rev 1 00 Jan 10 2008 Page 758 of 1658 REJ09B0261 0100 ...
Страница 828: ...17 Power Down Mode Rev 1 00 Jan 10 2008 Page 798 of 1658 REJ09B0261 0100 ...
Страница 846: ...18 Timer Unit TMU Rev 1 00 Jan 10 2008 Page 816 of 1658 REJ09B0261 0100 ...
Страница 1292: ...24 Multimedia Card Interface MMCIF Rev 1 00 Jan 10 2008 Page 1262 of 1658 REJ09B0261 0100 ...
Страница 1326: ...25 Audio Codec Interface HAC Rev 1 00 Jan 10 2008 Page 1296 of 1658 REJ09B0261 0100 ...
Страница 1482: ...28 General Purpose I O Ports GPIO Rev 1 00 Jan 10 2008 Page 1452 of 1658 REJ09B0261 0100 ...
Страница 1538: ...30 User Debugging Interface H UDI Rev 1 00 Jan 10 2008 Page 1508 of 1658 REJ09B0261 0100 ...
Страница 1688: ...Appendix Rev 1 00 Jan 10 2008 Page 1658 of 1658 REJ09B0261 0100 ...
Страница 1691: ......
Страница 1692: ...SH7785 Hardware Manual ...