PIC16LF1828T-I/ML View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16LF1828T-I/ML

28/40/44-Pin, Low-Power, High-Performance Microcontrollers with nanoWatt XLP Technology

Microchip Technology 

PIC16(L)F1824/1828

25.6.13.3 Bus Collision During a Stop

Condition

Bus collision occurs during a Stop condition if:

a) After the SDA pin has been deasserted and

allowed to float high, SDA is sampled low after

the BRG has timed out.

b) After the SCL pin is deasserted, SCL is sampled

low before SDA goes high.

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 SSP1ADD 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’ (Figure 25-37). If the SCL pin is sampled

low before SDA is allowed to float high, a bus collision

occurs. This is another case of another master

attempting to drive a data ‘0’ (Figure 25-38).

FIGURE 25-38:

BUS COLLISION DURING A STOP CONDITION (CASE 1)

TBRG

TBRG

TBRG

SDA

SCL

SDA asserted low

PEN

BCL1IF

P

SSP1IF

SDA sampled

low after TBRG,

set BCL1IF

‘0’

‘0’

FIGURE 25-39:

BUS COLLISION DURING A STOP CONDITION (CASE 2)

TBRG

TBRG

TBRG

SDA

SCL

Assert SDA

SCL goes low before SDA goes high,

set BCL1IF

PEN

BCL1IF

P

‘0’

SSP1IF

‘0’

 2010 Microchip Technology Inc.

Preliminary

DS41419B-page 289

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