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344
CHAPTER 18 SERIAL INTERFACE IIC0 (
μ
PD780078Y SUBSERIES ONLY)
User
’
s Manual U14260EJ3V1UD
Figure 18-6. Format of IIC Status Register 0 (IICS0) (2/3)
COI0
Detection of matching addresses
0
Addresses do not match.
1
Addresses match.
Condition for clearing (COI0 = 0)
Condition for setting (COI0 = 1)
When a start condition is detected
When a stop condition is detected
Cleared by LREL0 = 1 (exit from communications)
When IICE0 changes from 1 to 0 (operation stop)
When RESET is input
When the received address matches the local
address (slave address register 0 (SVA0))
(set at the rising edge of the eighth clock).
TRC0
Detection of transmit/receive status
0
Receive status (other than transmit status). The SDA0 line is set to high impedance.
1
Transmit status. The value in the SO0 latch is enabled for output to the SDA0 line (valid starting at
the falling edge of the first byte
’
s ninth clock).
Condition for clearing (TRC0 = 0)
Condition for setting (TRC0 = 1)
<Both master and slave>
Master
When a stop condition is detected
Cleared by LREL0 = 1 (exit from communications)
When a start condition is generated
When
“
0
”
is output to the first byte
’
s LSB
When IICE0 changes from 1 to 0 (operation stop)
Cleared by WREL0 = 1
Note
(wait cancel)
When ALD0 changes from 0 to 1 (arbitration loss)
When RESET is input
<Master>
When
“
1
”
is output to the first byte
’
s LSB
(transfer direction specification bit)
<Slave>
When a start condition is detected
(transfer direction specification bit)
Slave
When
“
1
”
is input to the first byte
’
s LSB
(transfer direction specification bit)
When
“
0
”
is input to the first byte
’
s LSB
(transfer direction specification bit)
<When not used for communication>
Note
If the wait status is canceled by setting bit 5 (WREL0) of IIC control register 0 (IICC0) to 1 at the ninth
clock when bit 3 (TRC0) of IIC status register 0 (IICS0) is 1, TRC0 is cleared, and the SDA0 line goes
into a high-impedance state.
Remark
LREL0: Bit 6 of IIC control register 0 (IICC0)
IICE0:
Bit 7 of IIC control register 0 (IICC0)