Section 21 Serial Communication Interface with FIFO (SCIF)
Rev.1.00 Dec. 13, 2005 Page 794 of 1286
REJ09B0158-0100
21.6 Usage
Notes
Note the following when using the SCIF.
(1) SCFTDR Writing and the TDFE Flag
The TDFE flag in SCFSR is set when the number of transmit data bytes written in SCFTDR has
fallen to or below the transmit trigger number set by bits TTRG1 and TTRG0 in SCFCR. After
TDFE is set, transmit data up to the number of empty bytes in SCFTDR can be written, allowing
efficient continuous transmission.
However, if the number of data bytes written in SCFTDR is equal to or less than the transmit
trigger number, the TDFE flag will be set to 1 again, even after being read as 1 and cleared to 0.
TDFE clearing should therefore be carried out when SCFTDR contains more than the transmit
trigger number of transmit data bytes.
The number of transmit data bytes in SCFTDR can be found from SCTFDR.
(2) SCFRDR Reading and the RDF Flag
The RDF flag in SCFSR is set when the number of receive data bytes in SCFRDR has become
equal to or greater than the receive trigger number set by bits RTRG1 and RTRG0 in SCFCR.
After RDF is set, receive data equivalent to the trigger number can be read from SCFRDR,
allowing efficient continuous reception.
However, if the number of data bytes read in SCFRDR is equal to or greater than the trigger
number, the RDF flag will be set to 1 again even if it is cleared to 0. After the receive data is
read, clear the RDF flag readout to 0 in order to reduce the number of data bytes in SCFRDR to
less than the trigger number.
The number of receive data bytes in SCFRDR can be found from SCRFDR.
(3) Break Detection and Processing
If a framing error (FER) is detected, break signals can also be detected by reading the SCIF_RXD
pin value directly. In the break state the input from the SCIF_RXD pin consists of all 0s, so the
FER flag is set and the parity error flag (PER) may also be set.
Although the SCIF stops transferring receive data to SCFRDR after receiving a break, the receive
operation continues.
Summary of Contents for SH7780 Series
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Page 82: ...Section 1 Overview Rev 1 00 Dec 13 2005 Page 32 of 1286 REJ09B0158 0100 ...
Page 122: ...Section 3 Instruction Set Rev 1 00 Dec 13 2005 Page 72 of 1286 REJ09B0158 0100 ...
Page 146: ...Section 4 Pipelining Rev 1 00 Dec 13 2005 Page 96 of 1286 REJ09B0158 0100 ...
Page 196: ...Section 6 Floating Point Unit FPU Rev 1 00 Dec 13 2005 Page 146 of 1286 REJ09B0158 0100 ...
Page 292: ...Section 9 L Memory Rev 1 00 Dec 13 2005 Page 242 of 1286 REJ09B0158 0100 ...
Page 492: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Dec 13 2005 Page 442 of 1286 REJ09B0158 0100 ...
Page 674: ...Section 15 Clock Pulse Generator CPG Rev 1 00 Dec 13 2005 Page 624 of 1286 REJ09B0158 0100 ...
Page 692: ...Section 16 Watchdog Timer and Reset Rev 1 00 Dec 13 2005 Page 642 of 1286 REJ09B0158 0100 ...
Page 726: ...Section 18 Timer Unit TMU Rev 1 00 Dec 13 2005 Page 676 of 1286 REJ09B0158 0100 ...
Page 1032: ...Section 25 Audio Codec Interface HAC Rev 1 00 Dec 13 2005 Page 982 of 1286 REJ09B0158 0100 ...
Page 1150: ...Section 28 General Purpose I O GPIO Rev 1 00 Dec 13 2005 Page 1100 of 1286 REJ09B0158 0100 ...
Page 1184: ...Section 29 User Break Controller UBC Rev 1 00 Dec 13 2005 Page 1134 of 1286 REJ09B0158 0100 ...
Page 1266: ...Section 31 Electrical Characteristics Rev 1 00 Dec 13 2005 Page 1216 of 1286 REJ09B0158 0100 ...
Page 1328: ...Appendix Rev 1 00 Dec 13 2005 Page 1278 of 1286 REJ09B0158 0100 ...
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