![](http://datasheet.mmic.net.cn/30000/M30280M6-XXXHP_datasheet_2358793/M30280M6-XXXHP_177.png)
M16C/28 Group
Under development Preliminary specification
Specifications in this manual are tentative and subject to change.
14.1 UARTi (i=0 to 2)
Rev.0.60 2004.02.01
page 159 of N
REJ09B0047-0060Z
Figure 14.1.6. Serial I/O-related registers (3)
UARTi transmit/receive control register 0 (i=0 to 2)
Symbol
Address
After reset
U0C0 to U2C0
03A416, 03AC16, 037C16 000010002
b7
b6
b5
b4
b3
b2
b1
b0
Function
TXEPT
CLK1
CLK0
CRS
CRD
NCH
CKPOL
BRG count source
select bit
Transmit register empty
flag
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
CLK polarity select bit
CTS/RTS function
select bit
CTS/RTS disable bit
Data output select bit
0 0 : f1SIO or f2SIO is selected
0 1 : f8SIO is selected
1 0 : f32SIO is selected
1 1 : Must not be set
b1 b0
0 : LSB first
1 : MSB first
0 : Data present in transmit register (during transmission)
1 : No data present in transmit register
(transmission completed)
0 : CTS/RTS function enabled
1 : CTS/RTS function disabled
(P60, P64 and P73 can be used as I/O ports)
0 : TxDi/SDAi and SCLi pins are CMOS output
1 : TxDi/SDAi and SCLi pins are N-channel open-drain output
UFORM Transfer format select bit
(Note 2)
Effective when CRD = 0
0 : CTS function is selected (Note 1)
1 : RTS function is selected
Bit name
Bit
symbol
Note 1: Set the corresponding port direction bit for each CTSi pin to “0” (input mode).
Note 2: Effective for clock synchronous serial I/O mode, UART mode transfer data 8 bits long and special mode 2.
Note 3: CTS1/RTS1 can be used when the UCON register’s CLKMD1 bit = “0” (only CLK1 output) and the UCON register’s RCSP bit =
“0” (CTS0/RTS0 not separated).
RW
RO
(Note 3)
Note: When using multiple transfer clock output pins, make sure the following conditions are met:
U1MR register’s CKDIR bit = “0” (internal clock)
UART transmit/receive control register 2
Symbol
Address
After reset
UCON
03B016
X00000002
b7
b6
b5
b4
b3
b2
b1
b0
Bit
name
Bit
symbol
RW
Function
CLKMD0
CLKMD1
UART0 transmit
interrupt cause select bit
UART0 continuous
receive mode enable bit
0 : Continuous receive mode disabled
1 : Continuous receive mode enable
UART1 continuous
receive mode enable bit
UART1 CLK/CLKS
select bit 0
UART1 transmit
interrupt cause select bit
0 : Transmit buffer empty (Tl = 1)
1 : Transmission completed (TXEPT = 1)
0 : Transmit buffer empty (Tl = 1)
1 : Transmission completed (TXEPT = 1)
0 : CLK output is only CLK1
1 : Transfer clock output from multiple pins function
selected
0 : Continuous receive mode disabled
1 : Continuous receive mode enabled
Nothing is assigned. When write, set “0”. When read, its content is indeterminate.
U0IRS
U1IRS
U0RRM
U1RRM
UART1 CLK/CLKS
select bit 1 (Note)
Effective when CLKMD1 = “1”
0 : Clock output from CLK1
1 : Clock output from CLKS1
RCSP
Separate UART0
CTS/RTS bit
0 : CTS/RTS shared pin
1 : CTS/RTS separated (CTS0 supplied from the P64 pin)
RW
(b7)