deveopmen
Serial I/O
Preliminary Specifications REV.D
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M16C/80 (100-pin version) group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
128
Figure 1.16.8. Serial I/O-related registers (4)
Function
(During UART mode)
W
R
Function
(During clock synchronous
serial I/O mode)
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 : f
1
is selected
0 1 : f
8
is selected
1 0 : f
32
is selected
1 1 : Inhibited
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
0 : TXDi pin is CMOS output
1 : TXDi pin is N-channel
open drain output
UFORM Transfer format select bit
(Note 3)
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.
0 0 : f
1
is selected
0 1 : f
8
is selected
1 0 : f
32
is selected
1 1 : Inhibited
b1 b0
Valid when bit 4 = “0”
0 : CTS function is selected (Note 1)
1 : RTS function is selected (Note 2)
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)
0: TXDi pin is CMOS output
1: TXDi pin is N-channel
open drain output
Must always be “0”
Bit name
Bit
symbol
0 : CTS/RTS function enabled
1 : CTS/RTS function disabled
AA
AA
AA
AA
A
A
AA
AA
AA
AA
AA
AA
UARTi transmit/receive control register 0
b7
b6
b5
b4
b3 b2
b1
b0
Symbol
UiC0(i=3,4)
Address
032C
16
, 02FC
16
When reset
08
16
0 : LSB first
1 : MSB first