Mitsubishi microcomputers
M16C / 61 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Serial I/O
UARTi transmit buffer register
Symbol
U0TB
U1TB
U2TB
Address
When reset
(b15)
b7
(b8)
03A316, 03A216
03AB16, 03AA16
037B16, 037A16
Indeterminate
Indeterminate
Indeterminate
b0 b7
b0
Function
R W
Transmit data
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns out to be indeterminate.
UARTi receive buffer register
(b15)
b7
(b8)
b0 b7
Symbol
U0RB
U1RB
U2RB
Address
When reset
Indeterminate
Indeterminate
Indeterminate
b0
03A716, 03A616
03AF16, 03AE16
037F16, 037E16
Function
(During clock synchronous
serial I/O mode)
Bit
symbol
Function
(During UART mode)
Bit name
R W
Receive data
Receive data
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns out to be indeterminate.
OER
Overrun error flag (Note)
0 : No overrun error
0 : No overrun error
1 : Overrun error found
1 : Overrun error found
FER
Framing error flag (Note)
Invalid
0 : No framing error
1 : Framing error found
PER
SUM
Parity error flag (Note)
Error sum flag (Note)
Invalid
Invalid
0 : No parity error
1 : Parity error found
0 : No error
1 : Error found
Note: Bits 15 through 12 are set to “0” when the serial I/O mode select bit (bits 2 to 0 at addresses 03A016
,
03A816 and 037816) are set to “000 ” or the receive enable bit is set to “0”.
2
(Bit 15 is set to “0” when bits 14 to 12 all are set to “0”.) Bits 14 and 13 are also set to “0” when the
lower byte of the UARTi receive buffer register (addresses 03A616, 03AE16 and 037E16) is read out.
UARTi bit rate generator
Symbol
U0BRG
U1BRG
U2BRG
Address
03A116
03A916
037916
When reset
Indeterminate
Indeterminate
Indeterminate
b7
b0
R W
Function
Values that can be set
0016 to FF16
Assuming that set value = n, BRGi divides the count source by
n + 1
Figure 1.17.4. Serial I/O-related registers (1)
91
MITSUBISHI [ Mitsubishi Group ]
