
Section 19 Serial Communication Interface with FIFO (SCIF)
Rev. 4.00 Sep. 14, 2005 Page 743 of 982
REJ09B0023-0400
Table 19.11 SCIF Interrupt Sources
Interrupt
Source
Description
DMAC
Activation
Priority on
Reset Release
ERI
Interrupt initiated by receive error (ER)
Not possible
High
RXI
Interrupt initiated by receive data FIFO full (RDF) or
data ready (DR)
*
Possible
BRI
Interrupt initiated by break (BRK) or overrun error
(ORER)
Not possible
TXI
Interrupt initiated by transmit FIFO data empty
(TDFE)
Possible
Low
Note:
*
RXI interrupt by DR is only possible in the asynchronous mode.
19.6 Usage
Notes
Note the following when using the SCIF.
1. SCFTDR Writing and TDFE Flag
The TDFE flag in the serial status register (SCFSR) is set when the number of transmit data
bytes written in the transmit FIFO data register (SCFTDR) has fallen below the transmit
trigger number set by bits TTRG1 and TTRG0 in the FIFO control register (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 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 the upper 8 bits of the FIFO
data count register (SCFDR).
2. SCFRDR Reading and RDF Flag
The RDF flag in the serial status register (SCFSR) is set when the number of receive data bytes
in the receive FIFO data register (SCFRDR) has become equal to or greater than the receive
trigger number set by bits RTRG1 and RTRG0 in the FIFO control register (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 in SCFRDR is equal to or greater than the trigger
number, the RDF flag will be set to 1 again if it is cleared to 0. RDF should therefore be
cleared to 0 after being read as 1 after all the receive data has been read.
Summary of Contents for HD6417641
Page 2: ...Rev 4 00 Sep 14 2005 Page ii of l...
Page 7: ...Rev 4 00 Sep 14 2005 Page vii of l...
Page 11: ...Rev 4 00 Sep 14 2005 Page xi of l USB Universal serial bus WDT Watch dog timer...
Page 12: ...Rev 4 00 Sep 14 2005 Page xii of l...
Page 28: ...Rev 4 00 Sep 14 2005 Page xxviii of l...
Page 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Page 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Page 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Page 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Page 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Page 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Page 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Page 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Page 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Page 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Page 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Page 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Page 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
Page 1032: ...Rev 4 00 Sep 14 2005 Page 982 of 982 REJ09B0023 0400 X X Y data addressing 52 X Y memory 193...
Page 1035: ......
Page 1036: ...SH7641 Hardware Manual...