
2011-2012 Microchip Technology Inc.
Preliminary
DS61168D-page 175
PIC32MX1XX/2XX
REGISTER 17-1:
I2CXCON: I2C CONTROL REGISTER
Bit
Range
Bit
31/23/15/7
Bit
30/22/14/6
Bit
29/21/13/5
Bit
28/20/12/4
Bit
27/19/11/3
Bit
26/18/10/2
Bit
25/17/9/1
Bit
24/16/8/0
31:24
U-0
—
23:16
U-0
—
15:8
R/W-0
U-0
R/W-0
R/W-1, HC
R/W-0
ON(1)
—
SIDL
SCLREL
STRICT
A10M
DISSLW
SMEN
7:0
R/W-0
R/W-0, HC
GCEN
STREN
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
Legend:
HC = Cleared in Hardware
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 31-16 Unimplemented: Read as ‘0’
bit 15
ON: I2C Enable bit(1)
1 = Enables the I2C module and configures the SDA and SCL pins as serial port pins
0 = Disables the I2C module; all I2C pins are controlled by PORT functions
bit 14
Unimplemented: Read as ‘0’
bit 13
SIDL: Stop in Idle Mode bit
1 = Discontinue module operation when device enters Idle mode
0 = Continue module operation in Idle mode
bit 12
SCLREL: SCLx Release Control bit (when operating as I2C slave)
1 = Release SCLx clock
0 = Hold SCLx clock low (clock stretch)
If STREN = 1:
Bit is R/W (i.e., software can write ‘0’ to initiate stretch and write ‘1’ to release clock). Hardware clear at
beginning of slave transmission. Hardware clear at end of slave reception.
If STREN = 0:
Bit is R/S (i.e., software can only write ‘1’ to release clock). Hardware clear at beginning of slave
transmission.
bit 11
STRICT: Strict I2C Reserved Address Rule Enable bit
1 = Strict reserved addressing is enforced. Device does not respond to reserved address space or generate
addresses in reserved address space.
0 = Strict I2C Reserved Address Rule not enabled
bit 10
A10M: 10-bit Slave Address bit
1 = I2CxADD is a 10-bit slave address
0 = I2CxADD is a 7-bit slave address
bit 9
DISSLW: Disable Slew Rate Control bit
1 = Slew rate control disabled
0 = Slew rate control enabled
bit 8
SMEN: SMBus Input Levels bit
1 = Enable I/O pin thresholds compliant with SMBus specification
0 = Disable SMBus input thresholds
Note 1: When using 1:1 PBCLK divisor, the user’s software should not read/write the peripheral’s SFRs in the
SYSCLK cycle immediately following the instruction that clears the module’s ON bit.