19-6337; Rev 0; 5/12 DS3231MPMB1 Peripheral Module General Description Features The DS3231MPMB1 peripheral module provides the necessary hardware to interface the DS3231M real-time clock (RTC) to any system that utilizes PmodK-compatible expansion ports configurable for I2C communication. The IC is a low-cost and extremely accurate I²C RTC. The device incorporates a battery input and maintains accurate timekeeping when main power to the device is interrupted. The integration of the microelectromechanical systems (MEMS) resonator enhances the long-term accuracy of the device and reduces the piece-part count in a manufacturing line. The device is available in the same footprint as the popular DS3231 RTC. S High Accuracy Time-of-Day and Date (±5ppm) from -40°C to +85°C Refer to the DS3231M IC data sheet for detailed information regarding operation of the IC. S Fully Assembled and Tested S 32.768kHz Square-Wave Output S Digital Temp Sensor with ±3NC Accuracy S 6-Pin Pmod-Compatible Connector (I2C) S Example Software Written in C for Portability S Secondary Header Allows Daisy-Chaining of Additional Modules on the I2C Bus S RoHS Compliant S Proven PCB Layout Ordering Information appears at end of data sheet. DS3231MPMB1 Peripheral Module Pmod is a trademark of Digilent Inc. __________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. DS3231MPMB1 Peripheral Module Component List DESIGNATION QTY DESCRIPTION BAT1 1 Battery holder Memory Protection Devices BH401 C1 1 1FF Q10%, 10V X7R ceramic capacitor (0603) TDK C1608X7R1A105K 1 0.1FF Q10%, 10V X74 ceramic capacitor (0603) Murata GRM188R71C104KA01D C2 DESIGNATION QTY J1 1 6-pin right-angle male header DESCRIPTION J2 1 8-pin (2 x 4) straight male header R1–R4 4 150I Q5% resistors (0603) R5–R8 4 4.7kI Q5% resistors (0603) U1 1 Q5ppm, I2C real-time clock (8 SO) Maxim MAX3231MZ+ — 1 PCB: EPCB3231PM1 Component Suppliers SUPPLIER PHONE WEBSITE Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com TDK Corp. 847-803-6100 www.component.tdk.com Note: Indicate that you are using the DS3231MPMB1 when contacting these component suppliers. Detailed Description I2C Interface The DS3231MPMB1 peripheral module can interface to the host in one of two ways. It can plug directly into a Pmod-compatible port (configured for I2C) through connector J1, or in this case, other I2C boards can attach to the same I2C bus through connector J2. Table 1. Connector J1 (I2C Communication) PIN SIGNAL DESCRIPTION 1 RST Active-low reset. This pin is an opendrain input/output. It is pulled low if VCC falls below threshold. This output is combined with a debounced pushbutton input function that can be activated to cause a reset request. 2 INT/SQW Active-low interrupt or 1Hz square-wave output. Interrupt function is activated when alarm occurs. I2C Interface (Daisy-Chaining Modules) Alternatively, the peripheral module can connect to other I2C-based Pmod modules using a 4-conductor ribbon cable connecting to the J2 connector. In this situation, pins 1-4 and 5-8 of J2 provide two connections to the I2C bus, allowing the module to be inserted into an I2C bus daisy-chain. Connector J1 provides connection of the module to the Pmod host. The pin functions and pin assignments adhere to the Pmod standard recommended by Digilent. See Table 1. 3 SCL I2C serial clock 4 SDA I2C serial data 5 GND Ground 6 VCC Power supply Table 2. Connector J2 (I2C Expansion) PIN SIGNAL 1 SCL I2C serial clock 2 SDA I2C serial data 3 GND Ground 4 VCC Power supply The peripheral module contains a battery holder for a lithium coin cell battery. The battery allows the IC to retain settings and time in the event of main power loss. 5 SCL 2-wire serial clock (same as pin 1 above) 6 SDA 2-wire serial data (same as pin 2 above) 7 GND Ground Note: A battery MUST be present for the DS3231MPMB1 to operate properly. 8 VCC Power supply The J2 connector allows the module to be connected through a daisy-chain from another I2C module and/or provide I2C and power connections to other I2C modules on the same bus. See Table 2. Battery Backup DESCRIPTION __________________________________________________________________ Maxim Integrated Products 2 DS3231MPMB1 Peripheral Module Software and FPGA Code Example software and drivers are available that execute directly without modification on several FPGA development boards tha support an integrated or synthesized microprocessor. These boards include the Digilent Nexys 3, Avnet LX9, and Avnet ZEDBoard, although other platforms can be added over time. Maxim provides complete Xilinx ISE projects containing HDL, Platform Studio, and SDK projects. In addition, a synthesized bit stream, ready for FPGA download, is provided for the demonstration application. The software project (for the SDK) contains several source files intended to accelerate customer evalu- ation and design. These include a base application (maximModules.c) that demonstrates module functionality and uses an API interface (maximDeviceSpecific Utilities.c) to set and access Maxim device functions within a specific module. The source code is written in standard ANSI C format, and all API documentation including theory/operation, register description, and function prototypes are documented in the API interface file (maximDeviceSpecificUtilities.h & .c). The complete software kit is available for download at www.maxim-ic.com. Quick start instructions are also available as a separate document. VCC R5 4.7k J1 1 2 3 4 5 6 R1 R2 R3 R4 150 150 150 150 RST SCL SDA GND VCC INT/SQW J2 1 2 3 4 5 6 7 8 VCC R6 4.7k R7 4.7k VCC VCC C1 1uF R8 4.7k GND 32KHZ 1 VCC 2 3 4 U1 DS3231M 32KHZ SCL VCC SDA INT/SQW VBAT RST GND VCC GND C2 8 1 32kHz SCL 7 SDA 6 VBAT 5 GND BAT1 1 2 B+ B- GND 0.1uF Figure 1. DS3231MPMB1 Peripheral Module Schematic __________________________________________________________________ Maxim Integrated Products 3 DS3231MPMB1 Peripheral Module Figure 2. DS3231MPMB1 Peripheral Module Component Placement Guide—Component Side Figure 3. DS3231MPMB1 Peripheral Module PCB Layout—Component Side Figure 4. DS3231MPMB1 Peripheral Module PCB Layout—Inner Layer 1 (Power) __________________________________________________________________ Maxim Integrated Products 4 DS3231MPMB1 Peripheral Module Figure 5. DS3231MPMB1 Peripheral Module PCB Layout—Inner Layer 2 (Ground) Figure 6. DS3231MPMB1 Peripheral Module PCB Layout—Solder Side Figure 7. DS3231MPMB1 Peripheral Module Component Placement Guide—Solder Side __________________________________________________________________ Maxim Integrated Products 5 DS3231MPMB1 Peripheral Module Ordering Information PART TYPE DS3231MPMB1# Peripheral Module #Denotes RoHS compliant. __________________________________________________________________ Maxim Integrated Products 6 DS3231MPMB1 Peripheral Module Revision History REVISION NUMBER REVISION DATE 0 5/12 DESCRIPTION Initial release PAGES CHANGED — Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2012 Maxim Integrated Products 7 Maxim is a registered trademark of Maxim Integrated Products, Inc.