upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 429

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

Serial
interface
UART6
Function
Details of Function
CKSR6: Clock
selection register
6
BRGC6: Baud
rate generator
control register 6
ASICL6:
Asynchronous
serial interface
control register 6
POWER6, TXE6,
RXE6: Bits 7, 6,
5 of ASIM6
UART mode
Parity types and
operation
Continuous
transmission
TXBF6 when
continuous
transmission: Bit
1 of ASIF6
TXSF6 when
continuous
transmission: Bit
1 of ASIF6
When the internal oscillation clock is selected as the clock to be supplied to the CPU, the
clock of the internal oscillator is divided and supplied as the count clock. If the base clock
is the internal oscillation clock, the operation of serial interface UART6 is not guaranteed.
Make sure POWER6 = 0 when rewriting TPS63 to TPS60.
Make sure that bit 6 (TXE6) and bit 5 (RXE6) of the ASIM6 register = 0 when rewriting the
MDL67 to MDL60 bits.
The baud rate value is the output clock of the 8-bit counter divided by 2.
ASICL6 can be refreshed (the same value is written) by software during a communication
operation (when bit 7 (POWER6) and bit 6 (TXE6) of ASIM6 = 1 or bit 7 (POWER6) and bit
5 (RXE6) of ASIM6 = 1). Note, however, that communication is started by the refresh
operation because bit 6 (SBRT6) of ASICL6 is cleared to 0 when communication is
completed (when an interrupt signal is generated).
In the case of an SBF reception error, return the mode to the SBF reception mode. The
status of the SBRF6 flag is held (1).
Before setting the SBRT6 bit, make sure that bit 7 (POWER6) and bit 5 (RXE6) of ASIM6 =
1.
The read value of the SBRT6 bit is always 0. SBRT6 is automatically cleared to 0 after
SBF reception has been correctly completed.
Before setting the SBTT6 bit to 1, make sure that bit 7 (POWER6) and bit 6 (TXE6) of
ASIM6 = 1.
The read value of the SBTT6 bit is always 0. SBTT6 is automatically cleared to 0 at the
end of SBF transmission.
Before rewriting the DIR6 and TXDLV6 bits, clear the TXE6 and RXE6 bits to 0.
When using the 78K0/KB1+ to evaluate the program of a mask ROM version of the
78K0/KB1, set the SBTT6, SBL62, SBL61, and SBL60 bits to 0, 1, 0, 1, respectively.
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.
Take relationship with the other party of communication when setting the port mode
register and port register.
Fix the PS61 and PS60 bits to 0 when the device is incorporated in LIN.
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. Read only the TXBF6 flag when executing
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).
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.
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.
During continuous transmission, an overrun error may occur, which means that the next
transmission was completed before execution of INTST6 interrupt servicing after
transmission of one data frame. An overrun error can be detected by developing a
program that can count the number of transmit data and by referencing the TXSF6 flag.
APPENDIX D LIST OF CAUTIONS
User’s Manual U16846EJ3V0UD
Cautions
p. 234
p. 234
p. 235
p. 235
p. 236
p. 237
p. 237
p. 237
p. 237
p. 237
p. 237
p. 237
p. 239
p. 240
p. 244
p. 246
p. 246
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