M30222 Datasheet, PDF (129/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
Specifications in this manual are tentative and subject to change
M30222 Group
Rev. G
UART2 in I²C Mode
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
UART2 in I²C Mode
The UART2 special mode register (address 037716) is used to control UART2 in various ways.
Figure 1.104 shows the UART2 special mode register. Setting the I²C mode select bit (bit 1 of
U2SMR) to "1" selects I²C mode.
Table 1.41 shows the relation between the I²C mode select bit and respective control workings.
Since this function uses clock-synchronous serial I/O mode, set this bit to “0” in UART mode.
Table 1.41. Features in I²C mode
Function
1 Source for interrupt number 10 (Note 2)
Normal mode
Bus collision detection
2 Source for interrupt number 15 (Note 2)
3 Source for interrupt number 16 (Note 2)
4 UART2 transmission output delay
5 P70 at the time when UART2 is in use
6 P71 at the time when UART2 is in use
7 P72 at the time when UART2 is in use
8
DMA1 factor at the time when 1 1 0 1 is assigned
to the DMA request factor selection bits
UART2 transmission
UART2 reception
Not delayed
TxD2 (output)
RxD2 (input)
CLK2
UART2 reception
9 Noise filter width
10 Reading P71
15ns
Reading the terminal when 0 is
assigned to the direction register
11 Initial value of UART2 output
H level (when 0 is assigned to
the CLK polarity select bit)
Note 1: Make the settings given below when I ²C mode is in use.
Set 0 1 0 in bits 2, 1, 0 of the UART2 transmission/reception mode register.
Disable the RTS/CTS function. Choose the MSB First function.
Note 2: Follow the steps given below to switch from a factor to another.
1. Disable the interrupt of the corresponding number.
2. Switch from one source to another.
3. Reset the interrupt request flag of the corresponding number.
4. Set an interrupt level of the corresponding number.
Note 3: Set an initial value of SDA transmission output when serial I/O is invalid.
I²C mode (Note 1)
Start condition detection or stop
condition detection
No acknowledgment detection (NACK)
Acknowledgment detection (ACK)
Delayed
SDA (input/output) (Note 3)
SCL (input/output)
P72
Acknowledgment detection (ACK)
50ns
Reading the terminal regardless of the
value of the direction register
The value set in latch P70 when the port is
selected
1-130