Serial I/O (Special Modes)
164
Mitsubishi microcomputers
M16C / 62P Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
development
Preliminary Specifications Rev.1.0
Specifications in this manual are tentative and subject to change.
Table 1. 20. 2. Registers to Be Used and Settings in I
2
C Mode (1) (Continued)
Register
Bit
Function
Master
Slave
UiTB
3
UiRB
3
0 to 7
0 to 7
8
ABT
OER
---
SMD2 to SMD0
CKDIR
IOPOL
CLK1, CLK0
Set transmission data
Reception data can be read
ACK or NACK is set in this bit
Arbitration lost detection flag
Overrun error flag
Set a transfer rate
Set to ‘010
2
’
Set to “0”
Set to “0”
Select the count source for the UiBRG
register
Invalid because CRD = 1
Transmit buffer empty flag
Set to “1”
Set to “1”
2
Set to “0”
Set to “1”
Set this bit to “1” to enable transmission
Transmit buffer empty flag
Set this bit to “1” to enable reception
Reception complete flag
Invalid
Set to “0”
Set transmission data
Reception data can be read
ACK or NACK is set in this bit
Invalid
Overrun error flag
Invalid
Set to ‘010
2
’
Set to “1”
Set to “0”
Invalid
UiBRG
UiMR
3
UiC0
CRS
TXEPT
CRD
NCH
CKPOL
UFORM
TE
TI
RE
RI
U2IRS
1
U2RRM
1
,
UiLCH, UiERE
IICM
ABC
Invalid because CRD = 1
Transmit buffer empty flag
Set to “1”
Set to “1”
2
Set to “0”
Set to “1”
Set this bit to “1” to enable transmission
Transmit buffer empty flag
Set this bit to “1” to enable reception
Reception complete flag
Invalid
Set to “0”
UiC1
UiSMR
Set to “1”
Select the timing at which arbitration-lost
is detected
Bus busy flag
Set to “0”
Refer to Table 1.20.4.
Set this bit to “1” to enable clock
synchronization
Set this bit to “1” to have SCLi output
fixed to “L” at the falling edge of the 9th
bit of clock
Set this bit to “1” to have SDAi output
stopped when arbitration-lost is detected
Set to “0”
Set to “1”
Invalid
BBS
3 to 7
Bus busy flag
Set to “0”
Refer to Table 1.20.4.
Set to “0”
UiSMR2 IICM2
CSC
SWC
Set this bit to “1” to have SCLi output
fixed to “L” at the falling edge of the 9th
bit of clock
Set to “0”
ALS
STAC
Set this bit to “1” to initialize UARTi at
start condition detection
Set this bit to “1” to have SCLi output
forcibly pulled low
Set this bit to “1” to disable SDAi output
Set to “0”
Set to “0”
Refer to Table 1.20.4
Set the amount of SDAi digital delay
SWC2
Set this bit to “1” to have SCLi output
forcibly pulled low
Set this bit to “1” to disable SDAi output
Set to “0”
SDHI
7
UiSMR3 0, 2, 4 and NODC Set to “0”
CKPH
DL2 to DL0
i=0 to 2
Notes:
1. Set the U0C1 and U1C1 register bit 4 and bit 5 to “0”. The U0IRS, U1IRS, U0RRM and U1RRM bits are
in the UCON register.
2. TxD2 pin is N channel open-drain output. Set the NCH bit in the U2C0 register to “0”.
3. Not all register bits are described above. Set those bits to “0” when writing to the registers in I
2
C mode.
Refer to Table 1.20.4
Set the amount of SDAi digital delay