
CHAPTER 17 I
2C BUS
Preliminary User’s Manual U16541EJ1V0UM
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Table 17-5. Status During Arbitration and Interrupt Request Signal 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 ACK signal 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 output (when IICCn.SPIEn bit = 1)
Note 2
When the SDA0n pin is at low level while attempting to
output a restart condition
At falling edge of eighth or ninth clock following byte transfer
Note 1
When stop condition is detected while attempting to
output a restart condition
When stop condition is output (when IICCn.SPIEn bit = 1)
Note 2
When the DSA0n pin is at low level while attempting to
output a stop condition
When the SCL0n pin is at low level while attempting to
output a restart condition
At falling edge of eighth or ninth clock following byte transfer
Note 1
Notes 1.
When the WTIMn bit of the IICCn register = 1, an interrupt request signal occurs at the falling edge of
the ninth clock. When the WTIMn bit = 0 and the extension code’s slave address is received, an
interrupt request signal occurs at the falling edge of the eighth clock (n = 0 to 2).
2.
When there is a possibility that arbitration will occur, set the SPIEn bit = 1 for master device operation
(n = 0 to 2).
17.13 Wakeup Function
The I
2C bus slave function is a function that generates an interrupt request signal (INTIICn) when a local address
and extension code have been received.
This function makes processing more efficient by preventing unnecessary interrupt request signals from occurring
when addresses do not match.
When a start condition is detected, wake-up standby mode is set. This wake-up standby mode is in effect while
addresses are transmitted due to the possibility that an arbitration loss may change the master device (which has
output a start condition) to a slave device.
However, when a stop condition is detected, the SPIEn bit of the IICCn register is set regardless of the wake up
function, and this determines whether interrupt request signals are enabled or disabled (n = 0 to 2).