Datasheet

78K0/Kx2-L CHAPTER 14 SERIAL INTERFACE UART6
R01UH0028EJ0400 Rev.4.00 466
Sep 27, 2010
14.4.2 Asynchronous serial interface (UART) mode
In this mode, data of 1 byte is transmitted/received following a start bit, and a full-duplex operation can be performed.
A dedicated UART baud rate generator is incorporated, so that communication can be executed at a wide range of
baud rates.
(1) Registers used
• Asynchronous serial interface operation mode register 6 (ASIM6)
• Asynchronous serial interface reception error status register 6 (ASIS6)
• Asynchronous serial interface transmission status register 6 (ASIF6)
• Clock selection register 6 (CKSR6)
• Baud rate generator control register 6 (BRGC6)
• Asynchronous serial interface control register 6 (ASICL6)
• Input switch control register (ISC)
• Port mode register 1 (PM1), port mode register 6 (PM6)
Note 1
• Port register 1 (P1), port register 6 (P6)
Note 1
• Port output mode register 6 (POM6)
Note 2
Notes 1. 78K0/KY2-L, 78K0/KA2-L: Port mode register 6 (PM6), port register 6 (P6)
78K0/KB2-L, 78K0/KC2-L: Port mode register 1 (PM1), port register 1 (P1)
2. In the 78K0/KY2-L and 78K0/KA2-L, this register is used when using serial interface UART6.
The basic procedure of setting an operation in the UART mode is as follows.
<1> Set the CKSR6 register (refer to Figure 14-8).
<2> Set the BRGC6 register (refer to Figure 14-9).
<3> Set bits 0 to 4 (ISRM6, SL6, CL6, PS60, PS61) of the ASIM6 register (refer to Figure 14-5).
<4> Set bits 0 and 1 (TXDLV6, DIR6) of the ASICL6 register (refer to Figure 14-10).
<5> Set bit 7 (POWER6) of the ASIM6 register to 1.
<6> Set bit 6 (TXE6) of the ASIM6 register to 1. → Transmission is enabled.
Set bit 5 (RXE6) of the ASIM6 register to 1. → Reception is enabled.
<7> Write data to transmit buffer register 6 (TXB6). → Data transmission is started.
Caution Take relationship with the other party of communication when setting the port mode register and
port register.