PIC16LC773-I/SS View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16LC773-I/SS

28/40-Pin, 8-Bit CMOS Microcontrollers w/ 12-Bit A/D

Microchip Technology 

8.2 MSSP I2C Operation

The MSSP module in I2C mode fully implements all

master and slave functions (including general call sup-

port) and provides interrupts on start and stop bits in

hardware to determine a free bus (multi-master func-

tion). The MSSP module implements the standard

mode specifications as well as 7-bit and 10-bit address-

ing.

Refer to Application Note AN578, "Use of the SSP

Module in the I 2C Multi-Master Environment."

A "glitch" filter is on the SCL and SDA pins when the pin

is an input. This filter operates in both the 100 kHz and

400 kHz modes. In the 100 kHz mode, when these pins

are an output, there is a slew rate control of the pin that

is independant of device frequency.

FIGURE 8-10: I2C SLAVE MODE BLOCK

DIAGRAM

Internal

data bus

Read

Write

SCL

SDA

SSPBUF reg

shift

clock

SSPSR reg

MSb

LSb

Match detect

Addr Match

SSPADD reg

Start and

Stop bit detect

Set, Reset

S, P bits

(SSPSTAT reg)

PIC16C77X

FIGURE 8-11: I2C MASTER MODE BLOCK

DIAGRAM

Read

SSPADD<6:0>

7

Baud Rate Generator

Internal

data bus

Write

SCL

SDA

SSPBUF reg

shift

clock

SSPSR reg

MSb

LSb

Match detect

Addr Match

SSPADD reg

Start and Stop bit

detect / generate

Set/Clear S bit

and

Clear/Set P bit

(SSPSTAT reg)

and Set SSPIF

Two pins are used for data transfer. These are the SCL

pin, which is the clock, and the SDA pin, which is the

data. The SDA and SCL pins that are automatically

configured when the I2C mode is enabled. The SSP

module functions are enabled by setting SSP Enable

bit SSPEN (SSPCON<5>).

The MSSP module has six registers for I2C operation.

They are the:

• SSP Control Register (SSPCON)

• SSP Control Register2 (SSPCON2)

• SSP Status Register (SSPSTAT)

• Serial Receive/Transmit Buffer (SSPBUF)

• SSP Shift Register (SSPSR) - Not directly acces-

sible

• SSP Address Register (SSPADD)

The SSPCON register allows control of the I2C opera-

tion. Four mode selection bits (SSPCON<3:0>) allow

one of the following I2C modes to be selected:

• I2C Slave mode (7-bit address)

• I2C Slave mode (10-bit address)

• I2C Master mode, clock = OSC/4 (SSPADD +1)

Before selecting any I2C mode, the SCL and SDA pins

must be programmed to inputs by setting the appropri-

ate TRIS bits. Selecting an I2C mode, by setting the

SSPEN bit, enables the SCL and SDA pins to be used

as the clock and data lines in I2C mode.

 1999-2013 Microchip Technology Inc.

Advance Information

DS30275B-page 63

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