MR-MINI-RTC Gravitech

TM 2 MR-MINI-RTC I C Real Time Clock Board User Manual GRAVITECH.US uResearch GRAVITECH GROUP Copyright 2007 MicroResearch GRAVITECH GROUP WWW.GRAVITECH.US TM 2 MR-MINI-RTC I C Real Time Clock Board User Manual Features: Description 2 I C bus interface operating supply The MR-MINI-RTC is a Real Time Clock voltage: 2.5V to 6V (RTC) board. It display time base such as Clock function with four year calendar clock, timer, and calendar. Moreover, it can be a counter for an external clock. The data 24 or 12 hour format 2 can be interface via I C bus. There are no Thermal shutdown and current limit external components required. This makes it protection perfect for embedded systems that need On-board variable capacitor for RTC. The board is small can compact in size frequency adjustment 2.20 x 1.70 inches. Jumpers setting configuration Small and compact in size There are two modes of operation RTC Four mounting holes on each corner mode and counter mode. When using RTC Male and female output headers mode, there is a variable capacitor for frequency crystal adjustment. This makes crystal create correct frequency result in Interfacing: accurate time base. There is a on-board battery backup when there is no power apply to the board. This enable RTC to run There are two set of jumpers must be continuously even without power supply. configure. The first set is DIS/ENA jumpers. When using counter mode (CNT), user can These jumpers connect R pulled-up to SDA, input pulse signal from external generated SCL and INT pins. If there are pulled-up source via a header pin. Moreover, there is resistors on the bus already, these jumpers an on-board push button switch so user can need to be in disable (DIS) positions. generate the pulse to test or experiment with Otherwise, the jumpers need to be on this feature. enable (ENA) position. The MR-MINI-RTC is designed base on LM2575-5 IC. It is a clock/calendar circuit based on a 2048-bit static CMOS RAM organized as 256 words by 8 bits. Addresses and data are transferred serially via the two- 2 line bidirectional I C bus. The built-in word address register is incremented automatically after each written or read data byte. FIG 1: Pulled-up R enable FIG 2: Pulled-up R disable Please take a look at PCF8583 datasheet for more information. Copyright 2007 MicroResearch GRAVITECH GROUP WWW.GRAVITECH.US