Serial Communication
Specifications in this manual are tentative and subject to change
Rev. E
MITSUBISHI MICROCOMPUTERS
M30245 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
130
Figure 1.92. Serial I/O-related registers (4)
Bit Symbol
Function
(clock synchronous
serial I/O mode)
Function
(UART mode)
R W
Symbol
UiSMR (i = 0 to 3)
Address
03A7
16, 036716, 033716, 032716
UARTi special mode register (i= 0 to 3)
O
Note 1: Only "0" may be written
Note 2: UART0 Timer A3 underflow signal, UART1: Timer A4 underlfow signal, UART2 :Timer A0
underflow signal.
When reset
00
16
Bit Name
IICM
ABC
BBS
LSYN
ABSCS
ACSE
SSS
I2C mode select bit
Arbitration lost detecting
flag control bit
Bus busy flag
SCLL sync output
enable bit
Bus collision detect
sampling clock
select bit
Auto-clear function
select bit of transmit
enable bit
Transmit start condition
select bit
0 : Normal mode
1 : I2C mode
0 : Update per bit
1 : Update per byte
0 : STOP detected
1 : START detected
0 : Disabled
1 : Enabled
Set to "0"
O
_
O
Set to "0"
Set to "0" (Note 1)
Set to "0"
0 : Rising edge of transfer clock
1 : Timer Ai underflow signal
(Note 2)
0 : No auto clear function
1 : Auto clear when bus occurs
0 : Ordinary
1 : Falling edge of RxDi
Bit Symbol
Function
R W
Symbol
UiSMR2 (i = 0 to 3)
Address
03A6
16, 036616, 033616, 032616
UARTi special mode register 2 (i= 0 to 3)
When reset
00
16
Bit Name
IICM2
CSC
SWC
ALS
STC
SWC2
SDHI
I2C mode select bit 2
Clock synchronous bit
SCL wait output bit
SDA output stop bit
UARTi initialize bit
SCL Wait output bit 2
SDA output inhibit bit
0 : NACK/ACK interrupt (DMA source-ACK)
Transfer to receive buffer at the rising edge
of last bit of receive clock. Receive interrupt
occurs at the rising edge of last bit of receive
clock.
1 : UART transfer/receive interrupt (DMA
source-UART receive) Transfer to receive
buffer at the falling edge of last bit of receive
clock. Receive interrupt occurs at the falling
edge of last bit of receive clock
0 : Disabled
1 : Enabled
0 : Disabled
1 : Enabled
0 : Disabled
1 : Enabled
0 : Disabled
1 : Enabled
0 : UARTi clock
1 : 0 output
0 : Disabled
1 : Enabled (high impedance)
O
_
b7
b0
b1
b2
b3
b4
b5
b6
b7
b0
b1
b2
b3
b4
b5
b6
Nothing is assigned.
Write "0" when writing to this bit. The value is indeterminate if read.
Nothing is assigned.
Write "0" when writing to this bit. The value is indeterminate if read.