
Rev.1.00
May 18, 2004
page 139 of 296
M306V7MG/MH/MJ/MJA-XXXFP, M306V7FG/FH/FJ/FJAFP
s Bit 7: Communication mode specification bit (master/slave specification bit: MST)
This bit is used for master/slave specification for data communication. When this bit is “0,” the slave is
specified, so that a START condition and a STOP condition generated by the master are received,
and data communication is performed in synchronization with the clock generated by the master.
When this bit is “1,” the master is specified and a START condition and a STOP condition are gener-
ated, and also the clocks required for data communication are generated on the SCL.
The MST bit is cleared to “0” in one of the following conditions.
Immediately after completion of 1-byte data transmission when arbitration lost is detected
When a STOP condition is detected.
When occurence of a START condition is disabled by the START condition duplication preventing
function (See note).
At reset
Note: The START condition duplication prevention function disables the following: the START condi-
tion generation; bit counter reset, and SCL output with the generation. This bit is valid from
setting of BB flag to the completion of 1-byte transmittion/reception (occurrence of transmission/
reception interrupt request) <IICIRQ>.
Fig. 2.11.36 I2Ci status register (i = 0, 1)
Fig. 2.11.37 Interrupt request signal generation timing
I2Ci status register (i = 0, 1)
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
Address
When reset
IIC0S1
02E216
0001000?2
IIC1S1
02EA16
0001000?2
LRB
Last receive bit
General call detecting
flag (See note)
0 : Last bit = “0”
1 : Last bit = “1”
(See note 1)
0 : No general call detected
1 : General call detected
(See note 1)
Slave address comparison
flag (See note)
0 : Address mismatch
1 : Address match
(See note 1)
0 : Not detected
1 : Detected
(See note 1)
AD0
AAS
AL
Arbitration lost detecting
flag (See note)
0 : Interrupt request issued
1 : No interrupt request issued (See note 2)
I
2C-BUS interface i
interrupt request bit
b7b6
0 0 : Slave receive mode
0 1 : Slave transmit mode
1 0 : Master receive mode
1 1 : Master transmit mode
PIN
0 : Bus free
1 : Bus busy
(See note 1)
Bus busy flag
Notes 1: These bits and flags can be read out, but cannot be written.
2: This bit can be written only “1.”
BB
Communication mode
specification bits
TRX
MST
Bit Symbol
Bit name
Function
R W
SCL
PIN
IICIRQ