PIC18F2480 MICROCHIP [Microchip Technology], PIC18F2480 Datasheet - Page 217

• Manufacturer Part Number: PIC18F2480
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with ECAN Technology, 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

17.4.8
To initiate a Start condition, the user sets the Start
condition enable bit, SEN (SSPCON2<0>). If the SDA
and SCL pins are sampled high, the Baud Rate Gener-
ator 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
the 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
contents of SSPADD<6:0> and resumes its count.
When the Baud Rate Generator times out (T
SEN bit (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.
I
CONDITION TIMING
2
C MASTER MODE START
Write to SEN bit occurs here
FIRST START BIT TIMING
SDA
SCL
PIC18F2480/2580/4480/4580
BRG
SDA = 1,
SCL = 1
T
BRG
), the
BRG
Preliminary
),
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:
Note:
T
Write to SSPBUF occurs here
BRG
1st bit
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
Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPCON2 is disabled until the Start
condition is complete.
2
C module is reset into its Idle state.
WCOL Status Flag
T
BRG
2nd bit
DS39637A-page 215