Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
Rev. 3.00 Jan 25, 2006 page 450 of 872
REJ09B0286-0300
16.7.6
Serial Data Transmission (Except in Block Transfer Mode)
Data transmission in smart card interface mode (except in block transfer mode) is different from
that in normal serial communication interface mode in that an error signal is sampled and data is
re-transmitted. Figure 16.29 shows the data re-transfer operation during transmission.
1. If an error signal from the receiving end is sampled after one frame of data has been
transmitted, the ERS bit in SSR is set to 1. Here, an ERI interrupt request is generated if the
RIE bit in SCR is set to 1. Clear the ERS bit to 0 before the next parity bit is sampled.
2. For the frame in which an error signal is received, the TEND bit in SSR is not set to 1. Data is
re-transferred from TDR to TSR allowing automatic data retransmission.
3.
If no error signal is returned from the receiving end, the ERS bit in SSR is not set to 1. In this
case, one frame of data is determined to have been transmitted including re-transfer, and the
TEND bit in SSR is set to 1. Here, a TXI interrupt request is generated if the TIE bit in SCR is
set to 1. Writing transmit data to TDR starts transmission of the next data.
Figure 16.31 shows a sample flowchart for transmission. All the processing steps are
automatically performed using a TXI interrupt request to activate the DTC. In transmission, the
TEND and TDRE flags in SSR are simultaneously set to 1, thus generating a TXI interrupt request
when TIE in SCR is set. This activates the DTC by a TXI request thus allowing transfer of
transmit data if the TXI interrupt request is specified as a source of DTC activation beforehand.
The TDRE and TEND flags are automatically cleared to 0 at data transfer by the DTC. If an error
occurs, the SCI automatically re-transmits the same data. During re-transmission, TEND remains
as 0, thus not activating the DTC. Therefore, the SCI and DTC automatically transmit the
specified number of bytes, including re-transmission in the case of error occurrence. However, the
ERS flag is not automatically cleared; the ERS flag must be cleared by previously setting the RIE
bit to 1 to enable an ERI interrupt request to be generated at error occurrence.
The above procedure also applies to the case in which RFU is activated by TEND in SCI_0 and
SCI_2.
When transmitting/receiving data using the DTC or RFU, be sure to set and enable them prior to
making SCI settings. For DTC and RFU settings, see section 7, Data Transfer Controller (DTC)
and section 8, RAM-FIFO Unit (RFU).
Содержание H8S/2158
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Страница 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Страница 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
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Страница 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Страница 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Страница 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Страница 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Страница 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Страница 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Страница 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Страница 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Страница 744: ...Section 20 Encryption Operation Circuit DES and GF Rev 3 00 Jan 25 2006 page 690 of 872 REJ09B0286 0300...
Страница 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Страница 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Страница 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Страница 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Страница 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Страница 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Страница 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...