PIC16F872-I/SP Microchip Technology Inc., PIC16F872-I/SP Datasheet - Page 79

• Manufacturer Part Number: PIC16F872-I/SP
• Description: 28 PIN, 7 KB FLASH, 128 RAM, 22 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F872-I/SP

• A/d Inputs: 5-Channel, 10-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 64 Bytes
• Input Output: 22
• Interface: I2C/SPI
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

9.2.18.3
Bus collision occurs during a STOP condition if:
a)
b)
FIGURE 9-25:
FIGURE 9-26:
© 2006 Microchip Technology Inc.
After the SDA pin has been de-asserted and
allowed to float high, SDA is sampled low after
the BRG has timed out.
After the SCL pin is de-asserted, SCL is sam-
pled low before SDA goes high.
SSPIF
BCLIF
SDA
SCL
PEN
BCLIF
P
SSPIF
SDA
PEN
SCL
P
Bus Collision During a STOP
Condition
'0'
'0'
'0'
'0'
BUS COLLISION DURING A STOP CONDITION (CASE 1)
BUS COLLISION DURING A STOP CONDITION (CASE 2)
SDA asserted low
Assert SDA
T
BRG
T
BRG
T
BRG
T
BRG
The STOP condition begins with SDA asserted low.
When SDA is sampled low, the SCL pin is allowed to
float. When the pin is sampled high (clock arbitration),
the baud rate generator is loaded with SSPADD<6:0>
and counts down to 0. After the BRG times out, SDA is
sampled. If SDA is sampled low, a bus collision has
occurred. This is due to another master attempting to
drive a data '0'. If the SCL pin is sampled low before
SDA is allowed to float high, a bus collision occurs. This
is a case of another master attempting to drive a data
'0' (Figure 9-25).
SCL goes low before SDA goes high,
set BCLIF
T
BRG
T
BRG
PIC16F872
'0'
'0'
SDA sampled
low after T
set BCLIF
DS30221C-page 77
BRG
,