DocID018909 Rev 11
853/1731
RM0090
Inter-integrated circuit (I
2
C) interface
864
Note:
When the STOP, START or PEC bit is set, the software must not perform any write access
to I2C_CR1 before this bit is cleared by hardware. Otherwise there is a risk of setting a
second STOP, START or PEC request.
27.6.2 I
2
C Control register 2 (I2C_CR2)
Address offset: 0x04
Reset value: 0x0000
Bit 2 Reserved, must be kept at reset value
Bit 1
SMBUS
: SMBus mode
0: I
2
C mode
1: SMBus mode
Bit 0
PE
: Peripheral enable
0: Peripheral disable
1: Peripheral enable
Note: If this bit is reset while a communication is on going, the peripheral is disabled at the
end of the current communication, when back to IDLE state.
All bit resets due to PE=0 occur at the end of the communication.
In master mode, this bit must not be reset before the end of the communication.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
LAST
DMA
EN
ITBUF
EN
ITEVTE
N
ITERR
EN
Reserved
FREQ[5:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 15:13 Reserved, must be kept at reset value
Bit 12
LAST
: DMA last transfer
0: Next DMA EOT is not the last transfer
1: Next DMA EOT is the last transfer
Note: This bit is used in master receiver mode to permit the generation of a NACK on the last
received data.
Bit 11
DMAEN
: DMA requests enable
0: DMA requests disabled
1: DMA request enabled when TxE=1 or RxNE =1
Bit 10
ITBUFEN
: Buffer interrupt enable
0: TxE = 1 or RxNE = 1 does not generate any interrupt.
1: TxE = 1 or RxNE = 1 generates Event Interrupt (whatever the state of DMAEN)