
RM0008
Inter-integrated circuit (I
2
C) interface
Doc ID 13902 Rev 12
755/1096
26.6.7
Status register 2 (I2C_SR2)
Address offset: 0x18
Reset value:0x0000
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PEC[7:0]
DUALF
SMB
HOST
SMBDE
FAULT
GEN
CALL
Res.
TRA
BUSY
MSL
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
Bits 15:8
PEC[7:0]
Packet error checking register
This register contains the internal PEC when ENPEC=1.
Bit 7
DUALF
: Dual flag (Slave mode)
0: Received address matched with OAR1
1: Received address matched with OAR2
–Cleared by hardware after a Stop condition or repeated Start condition, or when PE=0.
Bit 6
SMBHOST
: SMBus host header (Slave mode)
0: No SMBus Host address
1: SMBus Host address received when SMBTYPE=1 and ENARP=1.
–Cleared by hardware after a Stop condition or repeated Start condition, or when PE=0.
Bit 5
SMBDEFAULT
: SMBus device default address (Slave mode)
0: No SMBus Device Default address
1: SMBus Device Default address received when ENARP=1
–Cleared by hardware after a Stop condition or repeated Start condition, or when PE=0.
Bit 4
GENCALL
: General call address (Slave mode)
0: No General Call
1: General Call Address received when ENGC=1
–Cleared by hardware after a Stop condition or repeated Start condition, or when PE=0.
Bit 3 Reserved, forced by hardware to 0.
Bit 2
TRA
: Transmitter/receiver
0: Data bytes received
1: Data bytes transmitted
This bit is set depending on the R/W bit of the address byte, at the end of total address
phase.
It is also cleared by hardware after detection of Stop condition (STOPF=1), repeated Start
condition, loss of bus arbitration (ARLO=1), or when PE=0.
Bit 1
BUSY
:
Bus busy
0: No communication on the bus
1: Communication ongoing on the bus
–Set by hardware on detection of SDA or SCL low
–cleared by hardware on detection of a Stop condition.
It indicates a communication in progress on the bus. This information is still updated when
the interface is disabled (PE=0).