SERIAL I/O
11.4 Clock asynchronous serial I/O (UART) mode
UART0 transmit/receive mode register (Address 3016)
UART1 transmit/receive mode register (Address 3816)
UART0 baud rate register (BRG0) (Address 3116)
UART1 baud rate register (BRG1) (Address 3916)
b7
b0
b7
b0
1
Serial I/O mode select bit
b2 b1 b0
1 0 0: UART mode (7 bits)
Can be set to “0016” to “FF16.”
1 0 1: UART mode (8 bits)
1 1 0: UART mode (9 bits)
CTSi/RTSi are used together.
Internal/External clock select bit
0: Internal clock
CTSi/RTSi are separated.
1: External clock
Port P1 direction register (Address 516
b7 b0
)
Stop bit length select bit
0: 1 stop bit
1: 2 stop bits
0
0
Odd/Even parity select bit
0: Odd parity
1: Even parity
Pin CTS
Pin CTS
0
1
Parity enable bit
0: Parity is disabled.
1: Parity is enabled.
Sleep select bit
0: Sleep mode cleared (invalid)
1: Sleep mode selected
UART0 transmit interrupt control register (Address 7116)
UART1 transmit interrupt control register (Address 7316)
b0
b7
UART0 transmit/receive control register 0 (Address 3416)
UART1 transmit/receive control register 0 (Address 3C16)
Interrupt priority level select bits
When using interrupts, set these bits
to one of levels 1 to 7.
b7
b0
When disabling interrupts, set these
bits to level 0.
0
0
BRG count source select bits
b1 b0
0 0 : f
2
0 1 : f16
1 0 : f64
1 1 : f512
UART0 transmit buffer register (Addresses 3316, 3216)
UART1 transmit buffer register (Addresses 3B16, 3A16)
b15
b8 b7
b0
CTS/RTS function is select bit
0: CTS function selected
1: RTS function selected
Transmit data is set.
CTS/RTS enable bit
0: CTS/RTS function is enabled.
1: CTS/RTS function is disabled.
UART0 transmit/receive control register 1 (Address 3516)
UART1 transmit/receive control register 1 (Address 3D16)
b7
b0
Serial I/O pin control register (Address AC16)
b7 b0
1
Transmit enable bit
1: Transmission enabled
CTS0/RTS0 separate select bit
0: CTS
1: CTS
0
/RTS
/RTS
0
are used together.
are separated (Note).
0
0
CTS1/RTS1 separate select bit
0: CTS
1: CTS
1
/RTS
1
are used together.
are separated (Note).
1
/RTS
1
TxD
0: Functions as TxD
TxD /P1 switch bit
0: Functions as TxD
0/P13 switch bit
0
1
.
.
1
7
Transmission starts.
Note: The CLK
i
pin cannot be used when
separation is selected.
the CTS/RTS
i
i
(If the CTS function selected, transmission starts
when the CTS pin’s input level becomes “L.”)
(Refer to “[Precaution for clock
asynchronous serial I/O (UART)
mode].”)
i
Fig. 11.4.4 Initial setting example for relevant registers when transmitting
7906 Group User’s Manual Rev.2.0
11-41
RENESAS [ RENESAS TECHNOLOGY CORP ]
