
PIC18FXX39
DS30485A-page 136
Preliminary
2002 Microchip Technology Inc.
REGISTER 16-4:
SSPCON1: MSSP CONTROL REGISTER 1 (I2C MODE)
R/W-0
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
bit 7
bit 0
bit 7
WCOL: Write Collision Detect bit
In Master Transmit mode:
1
= A write to the SSPBUF register was attempted while the I2C conditions were not valid for
a transmission to be started (must be cleared in software)
0
= No collision
In Slave Transmit mode:
1
= The SSPBUF register is written while it is still transmitting the previous word (must be
cleared in software)
0
= No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit
bit 6
SSPOV: Receive Overflow Indicator bit
In Receive mode:
1
= A byte is received while the SSPBUF register is still holding the previous byte (must
be cleared in software)
0
= No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode
bit 5
SSPEN: Synchronous Serial Port Enable bit
1
= Enables the serial port and configures the SDA and SCL pins as the serial port pins
0
= Disables serial port and configures these pins as I/O port pins
Note:
When enabled, the SDA and SCL pins must be properly configured as input or output.
bit 4
CKP: SCK Release Control bit
In Slave mode:
1
= Release clock
0
= Holds clock low (clock stretch), used to ensure data setup time
In Master mode:
Unused in this mode
bit 3-0
SSPM3:SSPM0: Synchronous Serial Port Mode Select bits
1111
= I2C Slave mode, 10-bit address with START and STOP bit interrupts enabled
1110
= I2C Slave mode, 7-bit address with START and STOP bit interrupts enabled
1011
= I2C Firmware Controlled Master mode (Slave IDLE)
1000
= I2C Master mode, clock = FOSC / (4 * (SSPADD+1))
0111
= I2C Slave mode, 10-bit address
0110
= I2C Slave mode, 7-bit address
Note:
Bit combinations not specifically listed here are either reserved, or implemented in
SPI mode only.
Legend:
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