The DS1742 is a full-function, Y2KC-compliant, real-time clock/calendar (RTC) and 2k x 8 non-volatile static RAM. User access to all registers within the DS1742 is accomplished with a bytewide interface as shown in Figure 1. The Real Time Clock (RTC) information and control bits reside in the eight uppermost RAM locations. The RTC registers co-exist with the static RAM registers in the same address space, but cannot be accessed simultaneously.
The DS1742 is a full function, year 2000-compliant real-time clock/calendar (RTC) and 2k x 8 non-volatile static RAM. It features an integrated NV SRAM, real-time clock, crystal, power-fail control circuit, and a lithium energy source. The device maintains time accuracy of +1 minute per month at 25°C and retains data for over 10 years without power.
| Memory Size | 2k x 8 |
|---|---|
| Clock Accuracy | +1 minute per month |
| Operating Temperature (Commercial) | 0°C to +70°C |
| Access Time (5V) | 70 ns |
| Access Time (3.3V) | 120 ns |
No, the RTC is calibrated at the factory and does not require additional calibration.
Setting the OSC bit (bit 7 of the seconds register) to a 1 stops the oscillator.