CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U13850EJ4V0UM
263
Figure 10-10. IIC Status Register n (IICSn) (2/3)
After reset: 00H
R
Address: FFFFF342H, FFFFF352H
<7>
<6>
<5>
<4>
<3>
<2>
<1>
<0>
IICSn
MSTSn
ALDn
EXCn
COIn
TRCn
ACKDn
STDn
SPDn
(n = 0, 1)
EXCn
Detection of extension code reception
0
Extension code was not received.
1
Extension code was received.
Condition for clearing (EXCn = 0)
Condition for setting (EXCn = 1)
•
When a start condition is detected
•
When a stop condition is detected
•
Cleared by LRELn = 1
•
When IICEn changes from 1 to 0
•
When RESET is input
•
When the higher four bits of the received address data
is either “0000” or “1111” (set at the rising edge of the
eighth clock).
COIn
Detection of matching addresses
0
Addresses do not match.
1
Addresses match.
Condition for clearing (COIn = 0)
Condition for setting (COIn = 1)
•
When a start condition is detected
•
When a stop condition is detected
•
Cleared by LRELn = 1
•
When IICEn changes from 1 to 0
•
When RESET is input
•
When the received address matches the local address
(SVAn) (set at the rising edge of the eighth clock).
TRCn
Detection of transmit/receive status
0
Receive status (other than transmit status). The SDAn line is set for high impedance.
1
Transmit status. The value in the SO latch is enabled for output to the SDAn line (valid starting at the
falling edge of the first byte’s ninth clock).
Condition for clearing (TRCn = 0)
Condition for setting (TRCn = 1)
•
When a stop condition is detected
•
Cleared by LRELn = 1
•
When IICEn changes from 1 to 0
•
Cleared by WRELn = 1
Note
•
When ALDn changes from 0 to 1
•
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
When not used for communication
Master
•
When a start condition is generated
Slave
•
When “1” is input by the first byte’s LSB (transfer
direction specification bit)
Note
TRCn is cleared and SDAn line become high impedance when bit 5 (WRELn) of IIC control register n
(IICCn) is set and wait state is released at ninth clock with bit 3 (TRCn) of IIC status register n (IICSn)
= 1.
Remark
WRELn: Bit 5 of IIC control register n (IICCn)
LRELn: Bit 6 of IIC control register n (IICCn)
IICEn:
Bit 7 of IIC control register n (IICCn)