m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 285

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

SERIAL I/O
11.3 Clock synchronous serial I/O mode
Fig. 11.3.8 Initial setting example for relevant registers when receiving
11-30
b7
Serial I/O pin control register (Address AC
UART0 transmit/receive mode register (Address 30
UART1 transmit/receive mode register (Address 38
UART2 transmit/receive mode register (Address B0
UART0 transmit/receive control register 0 (Address 34
UART1 transmit/receive control register 0 (Address 3C
UART2 transmit/receive control register 0 (Address B4
b7
b7
0
0
0
b0
b0
b0
1
Internal/External clock select bit
BRG count source select bits
CTS/RTS function select bit
Transfer format select bit
CTS
CTS
TxD
TxD
CTS
TxD
Selection of clock synchronous serial
I/O mode
CTS/RTS enable bit
UARTi receive interrupt mode select bit
CLK polarity select bit
: It may be either “0” or “1.”
Notes 1: In the clock synchronous serial I/O
0: CTS
0: CTS
0: Functions as TxD
1: Functions as P1
0: Functions as TxD
1: Functions as P1
0: CTS
0: Functions as TxD
1: Functions as P8
0: Internal clock
1: External clock
0: CTS function selected
1: RTS function selected
0: CTS/RTS function is enabled.
1: CTS/RTS function is disabled
0: Reception interrupt
1: Reception error interrupt
0: At the rising edge of the transfer
1: At the falling edge of the transfer
b1 b0
0 0: f
0 1: f
1 0: f
1 1: f
0: LSB first
1: MSB first
0
1
2
clock, receive data is input.
clock, receive data is input.
0
1
2
/P1
/P1
/P8
/RTS
/RTS
/RTS
2
16
64
512
2: When only reception is performed, if
0
1
2
3
7
3
/RTS
/RTS
/RTS
16
switch bit (Note 2)
switch bit (Note 2)
switch bit (Note 2)
mode, CTS
be selected. (Refer to section “[Pre-
cautions for clock synchronous
serial I/O mode].”)
3
these bits = “1,” the TxD
used as a programmable I/O port
pin.
0
1
2
7
)
separate select bit
separate select bit
separate select bit
0
1
2
are used together (Note 1)
are used together (Note 1)
are used together (Note 1)
7905 Group User’s Manual Rev.1.0
1
3
7
3
.
.
16
16
0
1
.
16
2
i
.
.
/RTS
.
)
)
)
16
16
16
)
)
i
)
separation cannot
i
pin can be
i
UART0 receive interrupt control register (Address 72
UART1 receive interrupt control register (Address 74
UART2 receive interrupt control register (Address F2
When external clock is selected.
b7
UART0 baud rate register (BRG0) (Address 31
UART1 baud rate register (BRG1) (Address 39
UART2 baud rate register (BRG2) (Address B1
UART0 transmit buffer register (Address 32
UART1 transmit buffer register (Address 3A
UART2 transmit buffer register (Address B2
UART0 transmit/receive control register 1 (Address 35
UART1 transmit/receive control register 1 (Address 3D
UART2 transmit/receive control register 1 (Address B5
Port P1 direction register (Address 5
Port P8 direction register (Address 14
b7
b7
b7
b7
b7
0
Reception starts.
b0
0
0
1
Interrupt priority level select bits
When using interrupts, set these bits to
one of levels 1 to 7.
When disabling interrupts, set these bits
to level 0.
When internal clock is selected.
b0
b0
b0
b0
b0
1
Note: Set the receive enable bit
Pin RxD
Pin RxD
Transmit enable bit
Reception enable bit
Can be set to “00
Pin RxD
Dummy data is set.
1: Transmission enabled
1: Reception enabled
16
and the transmit enable
bit to “1” simultaneously.
16
)
0
1
)
2
16
16
16
16
16
16
)
)
)
)
)
)
16
16
16
16
)
)
)
” to “FF
16
16
16
16
)
)
)
”.