PIC16F1513T-I/SS View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16F1513T-I/SS

28-Pin Flash Microcontrollers with XLP Technology

Microchip Technology 

PIC16(L)F1512/3

20.6 I2C MASTER MODE

Master mode is enabled by setting and clearing the

appropriate SSPM bits in the SSPCON1 register and

by setting the SSPEN bit. In Master mode, the SDA and

SCK pins must be configured as inputs. The MSSP

peripheral hardware will override the output driver TRIS

controls when necessary to drive the pins low.

Master mode of operation is supported by interrupt

generation on the detection of the Start and Stop

conditions. The Stop (P) and Start (S) bits are cleared

from a Reset or when the MSSP module is disabled.

Control of the I2C bus may be taken when the P bit is

set, or the bus is Idle.

In Firmware Controlled Master mode, user code

conducts all I2C bus operations based on Start and

Stop bit condition detection. Start and Stop condition

detection is the only active circuitry in this mode. All

other communication is done by the user software

directly manipulating the SDA and SCL lines.

The following events will cause the SSP Interrupt Flag

bit, SSPIF, to be set (SSP interrupt, if enabled):

• Start condition detected

• Stop condition detected

• Data transfer byte transmitted/received

• Acknowledge transmitted/received

• Repeated Start generated

Note 1: The MSSP module, when configured in

I2C Master mode, does not allow queuing

of events. For instance, the user is not

allowed to initiate a Start condition and

immediately write the SSPBUF register to

initiate transmission before the Start con-

dition is complete. In this case, the SSP-

BUF will not be written to and the WCOL

bit will be set, indicating that a write to the

SSPBUF did not occur

2: When in Master mode, Start/Stop

detection is masked and an interrupt is

generated when the SEN/PEN bit is

cleared and the generation is complete.

20.6.1 I2C MASTER MODE OPERATION

The master device generates all of the serial clock

pulses and the Start and Stop conditions. A transfer is

ended with a Stop condition or with a Repeated Start

condition. Since the Repeated Start condition is also

the beginning of the next serial transfer, the I2C bus will

not be released.

In Master Transmitter mode, serial data is output

through SDA, while SCL outputs the serial clock. The

first byte transmitted contains the slave address of the

receiving device (7 bits) and the Read/Write (R/W) bit.

In this case, the R/W bit will be logic ‘0’. Serial data is

transmitted eight bits at a time. After each byte is

transmitted, an Acknowledge bit is received. Start and

Stop conditions are output to indicate the beginning

and the end of a serial transfer.

In Master Receive mode, the first byte transmitted

contains the slave address of the transmitting device

(7 bits) and the R/W bit. In this case, the R/W bit will be

logic ‘1’. Thus, the first byte transmitted is a 7-bit slave

address followed by a ‘1’ to indicate the receive bit.

Serial data is received via SDA, while SCL outputs the

serial clock. Serial data is received eight bits at a time.

After each byte is received, an Acknowledge bit is

transmitted. Start and Stop conditions indicate the

beginning and end of transmission.

A Baud Rate Generator is used to set the clock

frequency output on SCL. See Section 20.7 “Baud

Rate Generator” for more detail.

DS40001624C-page 206

 2012-2014 Microchip Technology Inc.

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