RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 13 ASYNCHRONOUS SERIAL INTERFACE LIN-UART (UARTF)
13.7.2 Response preparation error detection function
If response preparation (setting of the UFnNO, UFnRRQ, and UFnTRQ bits) is not performed before reception of the
first byte by a response is completed (sampling point of the stop bit (first bit)) when in automatic baud rate mode (UFnMD1,
UFnMD0 = 11B), a response preparation error flag (UFnRPE) is set, a status interrupt request signal (INTLSn) is
generated, and subsequent transmission and reception processing are stopped (responses are ignored) without data
being stored.
When only this product has performed response transmission, no response preparation error occurs, because
reception is not performed at the LRxDn pin. When response transmission is started (UFnTRQ = 1) after reception at the
LRxDn pin has been started, recognition can be performed by the occurrence of consistency errors.
LRxDn pin
INTLRn
UFnHDC flag
LRxDn pin
Sampling point
UFnNO bit “L”
UFnRRQ bit
UFnTRQ bit
INTLSn
UFnRPE flag
“L”
“L”
Figure 13-61. Response Preparation Error Occurrence Example
BF SF PID data data CSF
Clear
Sets UFnCLHDC bit to 1
BF wait successful
Start Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Stop
Transmission/
reception stopped
Caution If UFnCON = 0, no response preparation error will occur, because a BF reception wait state is entered after
communication of the number of bytes set using the UFnBUL3 to UFnBUL0 bits is completed.
If UFnCON = 1, a response preparation error check state is entered again after communication of the
number of bytes set using the UFnBUL3 to UFnBUL0 bits is completed.
A response preparation error will occur if a receive operation is started before setting UFnTRQ the next time
after response transmission is completed.
Remark n = 0, 1
R01UH0317EJ0004 Rev. 0.04 761
Feb. 22, 2013
All “L”