CHAPTER 16 I
2
C BUS
User’s Manual U16896EJ2V0UD
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Table 16-5. Status During Arbitration and Interrupt Request Generation Timing
Status During Arbitration
Interrupt Request Generation Timing
During address transmission
Read/write data after address transmission
During extension code transmission
Read/write data after extension code transmission
During data transmission
During acknowledgment transfer period after data
reception
When restart condition is detected during data transfer
At falling edge of eighth or ninth clock following byte transfer
Note 1
When stop condition is detected during data transfer
When stop condition is generated (when IICC0.SPIE0 bit = 1)
Note 2
When the SDA0 pin is at low level while attempting to
generate a restart condition
At falling edge of eighth or ninth clock following byte transfer
Note 1
When stop condition is detected while attempting to
generate a restart condition
When stop condition is generated (when SPIE0 bit = 1)
Note 2
When the SDA0 pin is at low level while attempting to
generate a stop condition
When the SCL0 pin is at low level while attempting to
generate a restart condition
At falling edge of eighth or ninth clock following byte transfer
Note 1
Notes 1.
When the IICC0.WTIM0 bit = 1, an INTIIC0 signal occurs at the falling edge of the ninth clock. When
the WTIM0 bit = 0 and the extension code’s slave address is received, an INTIIC0 signal occurs at the
falling edge of the eighth clock.
2.
When there is a possibility that arbitration will occur, set the SPIE0 bit = 1 for master device operation.
16.12 Wakeup Function
The I
2
C bus slave function is a function that generates an interrupt request signal (INTIIC0) when a local address or
extension code has been received. This function makes processing more efficient by preventing the unnecessary
INTIIC0 signal from occurring when addresses do not match.
When a start condition is detected, wakeup standby mode is set. This wakeup standby mode is in effect while
addresses are transmitted due to the possibility that an arbitration loss may change the master device (which has
generated a start condition) to a slave device.
However, when a stop condition is detected, the IICC0.SPIE0 bit is set regardless of the wakeup function, and this
determines whether the INTIIC0 signal is enabled or disabled.
