NXP Semiconductors K22F series, Reference Manual, Page: 1213 / 1407

Master
mode?
Tx/Rx?
Arbitration
lost?
IAAS=1?
Tx/Rx?
ACK from
receiver?
SRW=1?
IAAS=1?
Clear ARBL
2nd to
last byte to be
read?
Last byte
to be read?
RXAK=0?
Last byte
transmitted?
End of
address cycle
(master Rx)?
Write next
byte to Data reg
Set TXAK
Generate stop
signal (MST=0)
Write data
to Data reg
Set Tx mode
Transmit
next byte
Read data from
Data reg
and store
Switch to
Rx mode
Set Rx mode
Switch to
Rx mode
Dummy read
from Data reg
Generate stop
signal (MST=0)
Read data from
Data reg
and store
Dummy read
from Data reg
Dummy read
from Data reg
N
Y
N
N
N
N
N
N
Y
Y
Y
Y
Y (read)
N (write)
N
Y
Rx Tx
Rx
Tx
Y
N
Address transfer
see note 1
Data transfer
see note 2
N
Y
Y
Y
Notes:
1. If general call is enabled, check to determine if the received address is a general call address (0x00).
If the received address is a general call address, the general call must be handled by user software.
2. When 10-bit addressing addresses a slave, the slave sees an interrupt following the first byte of the extended address.
Ensure that for this interrupt, the contents of the Data register are ignored and not treated as a valid data transfer.
Is STOPF
set?
N
Y
Is STARTF
set?
Y
N
Entry of ISR
Clear STARTF
Clear IICIF
Log Start Count++
Clear IICIF
Is this a Repeated-START
(Start Count > 1)?
N
Y
RTI
Clear STOPF
Clear IICIF
Zero Start Count
Multiple
addresses?
Y
Read Address from
Data register
and store
N
Figure 46-6. Typical I2C interrupt routine
Chapter 46 Inter-Integrated Circuit (I2C)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 1213