Datasheet

1300 Henley Court

Pullman, WA 99163

509.334.6306

www.digilentinc.com

PmodRTCC™ Reference Manual

Revised October 17, 2011

This manual applies to the PmodRTCC rev. A

DOC#: 502-218

Other product and company names mentioned may be trademarks of their respective owners.

Page 1 of 3

Overview

The PmodRTCC is a real-time clock/calendar powered by the Microchip MCP79410.

1 Functional Description

The PmodRTCC can communicate using I

C via the 8-pin header J2. Digilent boards implement several different I

interfaces.

2 Interfacing with the Pmod

All communications with the device must specify whether to write to the EEPROM or the RTCC registers/SRAM, as

well as a register address and a flag indicating whether the communication is a read or a write. This is followed by

the actual data transfer.

The PmodRTCC responds to two I

C addresses. Address ‘1010111’ is used for access to the EEPROM, and address

‘1101111’ is used for access to RTCC registers/SRAM.

The device is configured by writing to the registers within the device. The time registers can be set to specific

values and a control register sets their functionality.

The PmodRTCC.

 A real-time clock/calendar with lithium coin

cell back-up

 An I

C interface

 Multi-function pin output that can generate

a square wave

 Two available alarms

 128 bytes EEPROM

 64 bytes SRAM

Features include:

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300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com PmodRTCC™ Reference Manual Revised October 17, 2011 This manual applies to the PmodRTCC rev. A Overview The PmodRTCC is a real-time clock/calendar powered by the Microchip MCP79410. Features include:       A real-time clock/calendar with lithium coin cell back-up 2 An I C interface Multi-function pin output that can generate a square wave Two available alarms 128 bytes EEPROM 64 bytes SRAM The PmodRTCC.
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PmodRTCC™ Reference Manual Pin 1, 2 3, 4 5, 6 7, 8 Connector J2 – I2C Communications Signal Description SCL I2C Clock SDA I2C Data GND Power Supply Ground VCC Power Supply (3.3V) Table 1. Pinout description table. A full list of registers and their functionality, as well as communication specifications, can be found in the MCP79410 datasheet available at the Microchip website. 2 The I C interface standard uses two signal lines. These are I2C data (SDA) and serial clock (SCLK).
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PmodRTCC™ Reference Manual 2.4 Calibration The Calibration register in the MCP79410 can calibrate the device to correct for inaccuracies of the input clock source. It can add or subtract up to 254 clocks from the RTCC counter every minute. For more information, see the Calibration section of the MCP74910 datasheet. Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.