M16C6KA_15 Datasheet, PDF (92/270 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6KA Group
Serial I/O
UART1 transmit/receive control register 0
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
U1C0
Address
03AC16
When reset
0816
Bit
symbol
Bit name
CLK0
CLK1
BRG count source
selection bits
CRS CTS/RTS function
selection bit
TXEPT Transmit register empty
flag
Function
(During clock synchronous
serial I/O mode)
b1 b0
0 0 : f1 is selected
0 1 : f8 is selected
1 0 : f32 is selected
1 1 : Inhibited
Valid when bit 4 = “0”
0 : CTS function is selected (Note 1)
1 : RTS function is selected (Note 2)
0 : Data present in transmit register
(during transmission)
1 : No data present in transmit
register (transmission completed)
Function
(During UART mode)
RW
b1 b0
0 0 : f1 is selected
0 1 : f8 is selected
1 0 : f32 is selected
1 1 : Inhibited
Valid when bit 4 = “0”
0 : CTS function is selected (Note 1)
1 : RTS function is selected (Note 2)
0 : Data present in transmit register
(during transmission)
1 : No data present in transmit
register (transmission completed)
CRD CTS/RTS disable bit
0 : CTS/RTS function enabled
1 : CTS/RTS function disabled
(Pins function as
programmable I/O port)
NCH
Data output selection bit 0 : TXD1 pin is CMOS output
1 : TXD1 pin is N-channel open-
drain output
CKPOL
CLK polarity selection bit 0 : Transmit data is output at
falling edge of transfer clock
and receive data is input at
rising edge
1 : Transmit data is output at
rising edge of transfer clock
and receive data is input at
falling edge
UFORM Transfer format selection 0 : LSB first
bit (Note 3)
1 : MSB first
0 : CTS/RTS function enabled
1 : CTS/RTS function disabled
(Pins function as programmable
I/O port)
0: TXD1 pin is CMOS output
1: TXD1 pin is N-channel open-drain
output
Must always be “0”
0 : LSB first
1 : MSB first
Note 1: Set the corresponding port direction register to “0”.
Note 2: The settings of the corresponding port register and port direction register are invalid.
Note 3: Only clock synchronous serial I/O mode and 8-bit UART mode are valid.
Fig.GA-5 Serial I/O-related registers (3)
Rev.1.00 Jul 16, 2004 page 90 of 266
REJ03B0100-0100Z