DS1285, DS1287, DS1287A Real-time clock with 50 bytes RAM. DS1287(A) has built-in quartz crystal and lihium battery, and therefore the X1, X2 and VBAT pins are no-connect. On the (older) DS1287 the /RCLR pin is no-connect as well. +--------------+ MOT |1 +--+ 24| VCC X1 |2 23| SQW X2 |3 22| AD0 |4 21| /RCLR AD1 |5 20| VBAT AD2 |6 DS1285 19| /INT AD3 |7 18| /RST AD4 |8 17| DS AD5 |9 16| GND AD6 |10 15| R//W AD7 |11 14| AS GND |12 13| /CE +--------------+ [This information is part of the GIICM]