PIC16LF1826-I/SS View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16LF1826-I/SS

18/20/28-Pin Flash Microcontrollers with nanoWatt XLP Technology

Microchip Technology 

PIC16F/LF1826/27

24.6.13.3 Bus Collision During a Stop

Condition

Bus collision occurs during a Stop condition if:

a) After the SDAx pin has been deasserted and

allowed to float high, SDAx is sampled low after

the BRG has timed out.

b) After the SCLx pin is deasserted, SCLx is

sampled low before SDAx goes high.

The Stop condition begins with SDAx asserted low.

When SDAx is sampled low, the SCLx pin is allowed to

float. When the pin is sampled high (clock arbitration),

the Baud Rate Generator is loaded with SSPxADD and

counts down to 0. After the BRG times out, SDAx is

sampled. If SDAx is sampled low, a bus collision has

occurred. This is due to another master attempting to

drive a data ‘0’ (Figure 24-37). If the SCLx pin is

sampled low before SDAx is allowed to float high, a bus

collision occurs. This is another case of another master

attempting to drive a data ‘0’ (Figure 24-38).

FIGURE 24-38:

BUS COLLISION DURING A STOP CONDITION (CASE 1)

TBRG

TBRG

TBRG

SDAx

SCLx

SDAx asserted low

SDAx sampled

low after TBRG,

set BCLxIF

PEN

BCLxIF

P

’0’

SSPxIF

’0’

FIGURE 24-39: BUS COLLISION DURING A STOP CONDITION (CASE 2)

TBRG

TBRG

TBRG

SDAx

SCLx

Assert SDAx

SCLx goes low before SDAx goes high,

set BCLxIF

PEN

BCLxIF

P

’0’

SSPxIF

’0’

DS41391C-page 278

Preliminary

 2010 Microchip Technology Inc.

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