Serial I/O (Special Modes)
166
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.
Function
I
2
C mode (SMD2 to SMD0 = 010
2
, IICM = 1)
IICM2 = 0
(NACK/ACK interrupt)
CKPH = 1
(Clock delay)
(No clock delay)
Clock synchronous serial I/O
mode (SMD2 to SMD0 = 001
2
,
IICM = 0)
Factor of interrupt number
15, 17 and 19 (Note 1)(
Refer to Fig 1.20.2)
Factor of interrupt number
16, 18 and 20 (Note 1)(
Refer to Fig 1.20.2)
No acknowledgment
detection (NACK)
Rising edge of SCLi 9th bit
Acknowledgment detection
(ACK)
Rising edge of SCLi 9th bit
Start condition detection or stop condition detection
(Refer to Fig 1.20.4)
UARTi transmission output
delay
Functions of P6
3
, P6
7
and
P7
0
pins
Functions of P6
2
, P6
6
and
P7
1
pins
Functions of P6
1
, P6
5
and
P7
2
pins
Noise filter width
Read RxDi and SCLi pin
levels
Factor of interrupt number
6, 7 and 10 (Note 1)(Refer
to Fig 1.20.2)
Initial value of TxDi and
SDAi outputs
Initial and end values of
SCLi
DMA1 factor (Refer to Fig
1.20.2)
Store received data
UARTi transmission
Transmission started or
completed (selected by UiIRS)
UARTi reception
When 8th bit received
CKPOL = 0 (rising edge)
CKPOL = 1 (falling edge)
CKPOL = 0 (rising edge)
CKPOL = 1 (falling edge)
Not delayed
TxDi output
RxDi input
CLKi input or output selected
15ns
Possible when the
corresponding port direction bit
= 0
CKPOL = 0 (H)
CKPOL = 1 (L)
Delayed
SDAi input/output
SCLi input/output
(Cannot be used in I
2
C mode)
H
200ns
Always possible no matter how the corresponding port direction bit is set
The value set in the port register before setting I
2
C mode (Note 2)
Timing for transferring data
from the UART reception
shift register to the UiRB
register
IICM2 = 1
(UART transmit/ receive interrupt)
CKPH = 0
(No clock delay)
CKPH = 1
(Clock delay)
UARTi transmission
Rising edge of
SCLi 9th bit
UARTi transmission
Falling edge of SCLi 9th bit
UARTi transmission
Falling edge of SCLi
next to the 9th bit
Rising edge of SCLi 9th bit
Falling edge of
SCLi 9th bit
Falling and rising
edges of SCLi 9th
bit
i = 0 to 2
Note 1: To change the interrupt sources from one to another, follow the procedure described below.
1. Disable the interrupt of the corresponding interrupt number to be changed.
2. Change interrupt sources from one to another.
3. Set the IR bit for the corresponding interrupt number to 0 (no interrupt request).
4. Set the IPL2 to IPL0 bits for the corresponding interrupt number.
Note 2: Set the initial value of SDAi output while the UiMR register’s SMD2 to SMD0 bits = ‘000
2
’ (serial I/O disabled).
Note 3: Second data transfer to UiRB register (Rising edge of SCLi 9th bit)
Note 4. First data transfer to UiRB register (Falling edge of SCLi 9th bit)
UARTi reception
Acknowledgment detection
(ACK)
1st to 8th bits are stored in
UiRB register bit 7 to bit 0
UARTi reception
Falling edge of SCLi 9th bit
1st to 7th bits are stored in UiRB register
bit 6 to bit 0, with 8th bit stored in UiRB
register bit 8
1st to 8th bits are stored in
UiRB register bit 0 to bit 7
L
Read UiRB register
Bit 6 to bit 0 as bit 7
to bit 1, and bit 8 as
bit 0 (Note 4)
Read received data
UiRB register status is read
directly as is
CKPH = 0
H
L
1st to 8th bits are
stored in UiRB
register bit 7 to bit 0
(Note 3)
Table 1.20.4. I
2
C Mode Functions