PIC18LF8720 Microchip Technology, PIC18LF8720 Datasheet - Page 187

• Manufacturer Part Number: PIC18LF8720
• Description: (PIC18LF6620/6520/8520/6620/8620/6720/8720) 64/80-Pin High-Performance / 64-Kbyte Enhanced Flash Microcontrollers
• Manufacturer: Microchip Technology

17.4.8
To initiate a Start condition, the user sets the Start Con-
dition Enable bit, SEN (SSPCON2<0>). If the SDA and
SCL pins are sampled high, the Baud Rate Generator
is reloaded with the contents of SSPADD<6:0> and
starts its count. If SCL and SDA are both sampled high
when the Baud Rate Generator times out (T
SDA pin is driven low. The action of the SDA being
driven low, while SCL is high, is the Start condition and
causes the S bit (SSPSTAT<3>) to be set. Following
this, the Baud Rate Generator is reloaded with the con-
tents of SSPADD<6:0> and resumes its count. When
the Baud Rate Generator times out (T
(SSPCON2<0>) will be automatically cleared by
hardware, the Baud Rate Generator is suspended,
leaving the SDA line held low and the Start condition is
complete.
FIGURE 17-19:
 2004 Microchip Technology Inc.
Note:
I
CONDITION TIMING
If at the beginning of the Start condition,
the SDA and SCL pins are already sam-
pled low, or if during the Start condition the
SCL line is sampled low before the SDA
line is driven low, a bus collision occurs,
the Bus Collision Interrupt Flag, BCLIF, is
set, the Start condition is aborted and the
I
2
2
C module is reset into its Idle state.
C MASTER MODE START
PIC18F6520/8520/6620/8620/6720/8720
Write to SEN bit occurs here
FIRST START BIT TIMING
SDA
SCL
BRG
), the SEN bit
BRG
SDA = 1,
SCL = 1
T
), the
BRG
Set S bit (SSPSTAT<3>)
T
S
BRG
At completion of Start bit,
hardware clears SEN bit
17.4.8.1
If the user writes the SSPBUF when a Start sequence
is in progress, the WCOL is set and the contents of the
buffer are unchanged (the write doesn’t occur).
and sets SSPIF bit
Note:
T
Write to SSPBUF occurs here
BRG
1st bit
Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPCON2 is disabled until the Start
condition is complete.
WCOL Status Flag
T
BRG
2nd bit
DS39609B-page 185