M16C80 Datasheet, PDF (143/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
16. Serial I/O
UARTi transmit/receive control register 0
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
UiC0(i=3,4)
Address
When reset
032C16, 02FC16
0816
Bit
symbol
Bit name
CLK0
CLK1
BRG count source
select bit
Function
(During clock synchronous
serial I/O mode)
Function
(During UART mode)
b1 b0
0 0 : f1 is selected
0 1 : f8 is selected
1 0 : f32 is selected
1 1 : Must not be set
b1 b0
0 0 : f1 is selected
0 1 : f8 is selected
1 0 : f32 is selected
1 1 : Must not be set
RW
CRS
TXEPT
CTS/RTS function
select bit
Valid when bit 4 = “0”
Valid when bit 4 = “0”
0 : CTS function is selected (Note 1) 0 : CTS function is selected (Note 1)
1 : RTS function is selected (Note 2) _{1 : RTS function is selected (Note 2)}
Transmit register empty
flag
0 : Data present in transmit
register (during transmission)
1 : No data present in transmit
register (transmission
completed)
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 0 : CTS/RTS function enabled
1 : CTS/RTS function disabled 1 : CTS/RTS function disabled
NCH Data output select bit
0 : TXDi pin is CMOS output
1 : TXDi pin is N-channel
open drain output
0: TXDi pin is CMOS output
1: TXDi pin is N-channel
open drain output
CKPOL CLK polarity select 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
Set to “0”
UFORM Transfer format select bit 0 : LSB first
(Note 3)
1 : MSB first
0 : LSB first
1 : MSB first
Note 1: Set the corresponding function select register A to I/O port, and port direction register to “0”.
Note 2: Select RTS output using the corresponding function select registers A and B.
Note 3: Valid only in clock syncronous serial I/O mode and 8 bits UART mode.
Figure 16.8 Serial I/O-related registers (4)
Rev.1.00 Aug. 02, 2005 ^{Page 132} of 329
REJ09B0187-0100