PIC18F4550-I/P Microchip Technology Inc., PIC18F4550-I/P Datasheet - Page 227

• Manufacturer Part Number: PIC18F4550-I/P
• Description: 40 PIN, 32 KB FLASH, 2048 RAM, FS-USB 2.0
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4550-I/P

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 34
• Interface: I2C/SPI/UART/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

19.4.8
To initiate a Start condition, the user sets the Start
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
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
(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 19-21:
© 2006 Microchip Technology Inc.
I
CONDITION TIMING
2
C MASTER MODE START
Write to SEN bit occurs here
FIRST START BIT TIMING
SDA
SCL
BRG
), the SEN bit
BRG
), the SDA
PIC18F2455/2550/4455/4550
SDA = 1,
SCL = 1
T
BRG
Preliminary
Set S bit (SSPSTAT<3>)
T
S
BRG
19.4.8.1
If the user writes the SSPBUF when a Start sequence
is in progress, the WCOL bit is set and the contents of
the buffer are unchanged (the write doesn’t occur).
At completion of Start bit,
hardware clears SEN bit
and sets SSPIF bit
Note:
Note:
T
Write to SSPBUF occurs here
BRG
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 five bits of
SSPCON2 is disabled until the Start
condition is complete.
2
1st bit
C module is reset into its Idle state.
WCOL Status Flag
T
BRG
2nd bit
DS39632C-page 225