APPENDIX D LIST OF CAUTIONS
User’s Manual U16898EJ3V0UD
397
(11/17)
Chapter
Classification
Function Details
of
Function
Cautions Page
Before setting the SBRT6 bit to 1, make sure that bit 7 (POWER6) and bit 5
(RXE6) of ASIM6 = 1. Moreover, after setting the SBRT6 bit to 1, do not clear the
SBRT6 bit to 0 before the SBF reception ends (an interrupt request signal is
generated).
p. 190
The read value of the SBRT6 bit is always 0. SBRT6 is automatically cleared to 0
after SBF reception has been correctly completed.
p. 190
Before setting the SBTT6 bit to 1, make sure that bit 7 (POWER6) and bit 6
(TXE6) of ASIM6 = 1. Moreover, after setting the SBTT6 bit to 1, do not clear the
SBTT6 bit to 0 before the SBF transmission ends (an interrupt request signal is
generated)
p. 190
The read value of the SBTT6 bit is always 0. SBTT6 is automatically cleared to 0
at the end of SBF transmission.
p. 190
ASICL6:
Asynchronous
serial interface
control register
6
Before rewriting the DIR6 and TXDLV6 bits, clear the TXE6 and RXE6 bits to 0.
p. 190
POWER6,
TXE6, and
RXE6: 7, 6, and
5 of ASIM6
Clear POWER6 to 0 after clearing TXE6 and RXE6 to 0 to set the operation stop
mode.
To start the operation, set POWER6 to 1, and then set TXE6 and RXE6 to 1.
p. 192
UART mode
Take relationship with the other party of communication into consideration when
setting the port mode register and port register.
p. 193
Parity types and
operation
Fix the PS61 and PS60 bits to 0 when the device is incorporated in LIN.
p. 197
The TXBF6 and TXSF6 flags of the ASIF6 register change from “10” to “11”, and
to “01” during continuous transmission. To check the status, therefore, do not use
a combination of the TXBF6 and TXSF6 flags for judgment. Judge whether
continuous transmission is possible or not by reading only the TXBF flag.
p. 199
Continuous
transmission
When the device is incorporated in a LIN, the continuous transmission function
cannot be used. Make sure that asynchronous serial interface transmission
status register 6 (ASIF6) is 00H before writing transmit data to transmit buffer
register 6 (TXB6).
p. 199
TXBF6 during
continuous
transmission:
Bit 1 of ASIF6
To transmit data continuously, write the first transmit data (first byte) to the TXB6
register. Be sure to check that the TXBF6 flag is “0”. If so, write the next transmit
data (second byte) to the TXB6 register. If data is written to the TXB6 register
while the TXBF6 flag is “1”, the transmit data cannot be guaranteed.
p. 199
To initialize the transmission unit upon completion of continuous transmission, be
sure to check that the TXSF6 flag is “0” after generation of the transmission
completion interrupt, and then execute initialization. If initialization is executed
while the TXSF6 flag is “1”, the transmit data cannot be guaranteed.
p. 199
TXSF6 during
continuous
transmission:
Bit 0 of ASIF6
During continuous transmission, an error may occur such that the next
transmission is completed before execution of INTST6 interrupt servicing after
transmission of one data frame. As a countermeasure, such an error can be
detected by developing a program that can count the number of transmit data and
by referencing the TXSF6 flag.
p. 199
Be sure to read receive buffer register 6 (RXB6) even if a reception error occurs.
Otherwise, an overrun error will occur when the next data is received, and the
reception error status will persist.
p. 203
Reception is always performed with the “number of stop bits = 1”. The second
stop bit is ignored.
p. 203
Chapter 11
Soft
Serial
interface
UART6
Normal
reception
Be sure to read asynchronous serial interface reception error status register 6
(ASIS6) before reading RXB6.
p. 203