UART
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
357
Figure 2.5.7. UARTi-related registers (5)
Note: When using multiple pins to output the transfer clock, the following requirements must be met:
UART1 internal/external clock select bit (bit 3 at address 03A816) = “0”.
UART transmit/receive control register 2
Symbol
Address
When reset
UCON
03B016
X00000002
b7
b6
b5
b4
b3
b2
b1
b0
Bit
name
Bit
symbol
W
R
Function
(During UART mode)
Function
(During clock synchronous
serial I/O mode)
CLKMD0
CLKMD1
RCSP
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
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 : Normal mode
(CLK output is CLK1 only)
1 : Transfer clock output
from multiple pins
function selected
0 : Continuous receive
mode disabled
1 : Continuous receive
mode enabled
Nothing is assigned.
In an attempt to write to this bit, write “0”. The value, if read, turns out to be indeterminate.
0 : Transmit buffer empty (Tl = 1)
1 : Transmission completed
(TXEPT = 1)
0 : Transmit buffer empty (Tl = 1)
1 : Transmission completed
(TXEPT = 1)
Must always be “0”
U0IRS
U1IRS
U0RRM
U1RRM
0 : CTS/RTS shared pin
1 : CTS/RTS separated
0 : CTS/RTS shared pin
1 : CTS/RTS separated
Separate CTS/RTS bit
Invalid
CLK/CLKS select
bit 1 (Note)
Valid when bit 5 = “1”
0 : Clock output to CLK1
1 : Clock output to CLKS1
UART2 special mode register
Symbol
Address
When reset
U2SMR
037716
0016
b7
b6
b5
b4 b3
b2
b1
b0
Bit
name
Bit
symbol
W
R
Function
(During UART mode)
Function
(During clock synchronous
serial I/O mode)
ABSCS
ACSE
SSS
IIC mode selection bit
Bus busy flag
0 : STOP condition detected
1 : START condition detected
SCLL sync output
enable bit
Bus collision detect
sampling
clock select bit
Arbitration lost detecting
flag control bit
0 : Normal mode
1 : IIC mode
0 : Update per bit
1 : Update per byte
IICM
ABC
BBS
LSYN
0 : Ordinary
1 : Falling edge of RxD2
0 : Disabled
1 : Enabled
Transmit start condition
select bit
Must always be “0”
0 : Rising edge of transfer
clock
1 : Underflow signal of timer A0
Auto clear function
select bit of transmit
enable bit
0 : No auto clear function
1 : Auto clear at occurrence of
bus collision
Must always be “0”
Note: Nothing but "0" may be written.
(Note)
0
Reserved bit
Always set to “0”