Panasonic MN101L Series User Manual page 447

Detection of Communication Forcibly Terminated
When a start/stop condition is detected during the transmission/reception of data, including a slave address and R/
W bit, and ACK bit, SCnIICSTR.IIC3DATA_ERR is set to "1" as judged the serial communication is forced to be
terminated. When the situation occurs, clear IIC3DATA_ERR to "0" and restart a communication.
When the LSI is a master and the above situation occurs, the LSI continues communication until single byte is
transmitted (*) and SCnTIRQ occurs at the end of byte transmission.
(* If the arbitration lost occurs, the LSI changes to slave and stop communication.)
When the LSI is a slave and the above situation occurs, SCnTIRQ occurs and the LSI stop communication.
Arbitration Lost
When the LSI is a master, if transmission data doesn't match SDAn signal level, SCnSTR.IIC3ABT_LST is set
and SDAn and SCLn are released as judged it an arbitration lost.
The arbitration lost detection does not cause SCnTIRQ, but if the slave address sent from another master matches
the value of SCnAD after an arbitration lost detection, SCnTIRQ occurs. Confirm IIC3ABT_LST at the next
interrupt timing (SCnTIRQ or SCnSIRQ). Clear IIC3ABT_LST by program.
General Call Communication
When a general call is detected, SCnIICSTR.IIC3ADD_ACC and SCnIICSTR.IIC3GCALL are set and send
ACK bit. The value of SCnIICSTR.IIC3GCALL is valid only when SCnTIRQ occurs in the slave address recep-
tion.
Operation of Transmission Data Buffer register (TXBUFn) and Transmission Data Buffer Empty
Flag (SCnTEMP)
TXBUFn is a buffer to store transmission data. The data are transferred from TXBUFn to a transmission shift reg-
ister (SCnTRB) automatically. SCnTEMP is set to "1" by storing data to TXBUFn, and is cleared to "0" when the
data of TXBUFn is sent to SCnTRB and the communication starts.
When a data is written to TXBUFn during SCnTEMP being "1", the data can not be stored properly.
Operation of Reception Data Buffer Register (RXBUFn) and Reception Data Buffer Empty Flag
(SCnREMP)
RXBUFn is a buffer to store the reception data.
Received data is stored in a received shift register (SCnRDB) at first, and then it is moved to RXBUFn automati-
cally, SCnSTR.SCnREMP is set to "1" and SCnTIRQ occurs. SCnREMP is cleared to 0 by reading out RXBUFn.
When a data reception is received before the previous data is read from RXBUFn, SCnORE
is set.
.. ..
Overrun Error Flag
If the next data reception has been completed before a data read from RXBUFn, an overrun error occurs and
SCnSTR.SCnORE is set to "1". Clear SCnORE by program.
Chapter 13
Serial Interface
IIC Communication XIII - 59