
Unde
deeopmen
Preliminary Specifications REV.E
Specifications in this manual are tentative and subject to change.
UART2 Special Mode Register 2
Mitsubishi microcomputers
M30220 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
120
Bit 0 of the UART2 special mode register 2 (address 0376
16
) is used as the I
2
C mode selection bit 2.
Table 1.15.10 shows the types of control to be changed by I
2
C mode selection bit 2 when the I
2
C mode
selection bit is set to "1". Table 1.15.11 shows the timing characteristics of detecting the start condition
and the stop condition. Set the start/stop condition control bit (bit 7 of UART2 special mode register 2) to
"1" in I
2
C mode.
Function
IICM2 = 1
IICM2 = 0
Factor of interrupt number 15
No acknowledgment detection (NACK)
UART2 transmission (the rising edge
of the final bit of the clock)
Factor of interrupt number 16
Acknowledgment detection (ACK)
UART2 reception (the falling edge
of the final bit of the clock)
DMA1 factor at the time when 1 1 0 1
is assigned to the DMA request
factor selection bits
Acknowledgment detection (ACK)
UART2 reception (the falling edge of
the final bit of the clock)
Timing for transferring data from the
UART2 reception shift register to the
reception buffer.
The rising edge of the final bit of the
reception clock
The falling edge of the final bit of the
reception clock
Timing for generating a UART2
reception/ACK interrupt request
The rising edge of the final bit of the
reception clock
The falling edge of the final bit of the
reception clock
1
2
3
4
5
3 to 6 cycles < duration for setting-up (Note2)
3 to 6 cycles < duration for holding (Note2)
Note 1 : When the start/stop condition count bit is "1" .
Note 2 : "cycles" is in terms of the input oscillation frequency f(X
IN
) of the main clock.
Duration for
setting up
Duration for
holding
SCL
SDA
(Start condition)
SDA
(Stop condition)
Table 1.15.10. Functions changed by I
2
C mode selection bit 2
Table 1.15.11.
Timing characteristics of detecting the start condition and the stop condition(Note1)