
deveopmen
UARTi Special Mode Register
Preliminary Specifications REV.B
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M16C/80 (144-pin version) group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
152
UARTi special mode register
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)
0 : Normal mode
1 : I C mode
ABSCS
ACSE
SSS
I C mode select 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 : Update per bit
1 : Update per byte
IICM
ABC
BBS
LSYN
0 : Ordinary
1 : Falling edge of RxDi
0 : Disabled
1 : Enabled
Transmit start condition
select bit
Must always be “0”
0 : Rising edge of transfer
clock
1 : Underflow signal of timer Ai
Auto clear function
select bit of transmit
enable bit
AA
AA
AA
A
A
AA
A
A
A
A
A
A
0 : No auto clear function
1 : Auto clear at occurrence of
bus collision
Must always be “0”
Must always be “0”
Must always be “0”
Must always be “0”
Must always be “0”
Must always be “0”
Nothing is assigned.
This bit can neither be set nor reset. When read, its content is indeterminate.
Note 1: Nothing but "0" may be written.
Note 2: UART2 : timer A0 underflow signal, UART3 : timer A3 underflow signal, UART4 : timer A4
underflow signal.
(Note 2)
Symbol
UiSMR (i=2 to 4)
Address
When reset
00
16
0337
16
, 0327
16
, 02F7
16
UARTi special mode register 2
Symbol
UiSMR2 (i=2 to 4)
Address
When reset
00
16
0336
16
, 0326
16
, 02F6
16
b7
b6 b5
b4
b3
b2
b1
b0
Bit name
Bit
symbol
W
R
Function
IICM2
CSC
SWC
ALS
IIC mode select bit 2
SCL wait output bit
SDA output stop flag
Clock synchronous bit
Refer to Table 1.20.2.
0 : Disabled
1 : Enabled
STC
UARTi initialize bit
SWC2
SCL wait output bit 2
SDA output inhibit bit
SDHI
SHTC
Start/stop condition
control bit
AA
A
AA
A
A
AA
AA
AA
A
A
A
0 : Disabled
1 : Enabled
0 : Disabled
1 : Enabled
0 : Disabled
1 : Enabled
0 : UARTi clock
1 : 0 output
0 : Enabled
1 : Disabled (high impedance)
Must set to "1" in selecting IIC mode.
A
A
Figure 1.20.1. UART2 special mode register