Microchip Technology ARD00385 Data Sheet
2009-2011 Microchip Technology Inc.
DS39957D-page 315
PIC18F87K90 FAMILY
REGISTER 21-4:
SSPxCON1: MSSPx CONTROL REGISTER 1 (I
2
C™ MODE)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
WCOL
SSPOV
SSPEN
(
)
CKP
SSPM3
SSPM2
SSPM1
(
)
SSPM0
(
)
bit 7
bit 0
Legend:
R = Readable bit
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 7
WCOL:
Write Collision Detect bit
In Master Transmit mode:
1
1
= A write to the SSPxBUF register was attempted while the I
2
C conditions were not valid for a
transmission to be started (must be cleared in software)
0
= No collision
In Slave Transmit mode:
1
1
= The SSPxBUF 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.
This is a “don’t care” bit.
bit 6
SSPOV:
Receive Overflow Indicator bit
In Receive mode:
1
1
= A byte is received while the SSPxBUF 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.
This is a “don’t care” bit in Transmit mode.
bit 5
SSPEN:
Master Synchronous Serial Port Enable bit
1
= Enables the serial port and configures the SDAx and SCLx pins as the serial port pins
0
= Disables the serial port and configures these pins as I/O port pins
bit 4
CKP:
SCKx Release Control bit
In Slave mode:
1
1
= Releases clock
0
= Holds clock low (clock stretch); used to ensure data setup time
In Master mode:
Unused in this mode.
Unused in this mode.
bit 3-0
SSPM<3:0>:
Master Synchronous Serial Port Mode Select bits
1111
= I
2
C Slave mode: 10-bit address with Start and Stop bit interrupts enabled
1110
= I
2
C Slave mode: 7-bit address with Start and Stop bit interrupts enabled
1011
= I
2
C Firmware Controlled Master mode (slave Idle)
1001
= Load the SSPMSK register at the SSPxADD SFR address
)
1000
= I
2
C Master mode: Clock =
F
OSC
/(4 * (SSPxADD + 1))
0111
= I
2
C Slave mode: 10-bit address
0110
= I
2
C Slave mode: 7-bit address
Note 1:
When enabled, the SDAx and SCLx pins must be configured as inputs.
2:
Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
3:
When SSPM<3:0> = 1001, any reads or writes to the SSPxADD SFR address actually access the
SSPxMSK register.
SSPxMSK register.
4:
This mode is only available when 7-Bit Address Masking mode is selected (MSSPMSK Configuration bit is ‘1’).