CDP68HC68T1E  DIP16 CMOS Serial Real-Time Clock With RAM and Power Sense/Control

Descriotion

The CDP68HC68T1 Real-Time Clock provides a time/calendar function, a 32 byte static RAM, and a 3 wire Serial Peripheral Interface (SPI Bus). The primary function of the clock is to divide down a frequency input that can be supplied by the on-board oscillator in conjunction with an external crystal or by an external clock source. The internal oscillator can operate with a 32kHz, 1MHz, 2MHz, or 4MHz crystal. An external clock source with a 32kHz, 1MHz, 2MHz, 4MHz, 50Hz or 60Hz frequency can be used to drive the CDP68HC68T1. The time registers hold seconds, minutes, and hours, while the calendar registers hold day-of-week, date, month, and year information. The data is stored in BCD format. In addition, 12 or 24 hour operation can be selected. In 12 hour mode, an AM/PM indicator is provided. The T1 has a programmable output which can provide one of seven outputs for use elsewhere in the system.

Features 

• SPI (Serial Peripheral Interface) 
• Full Clock Features - Seconds, Minutes, Hours (12/24, AM/PM), Day of Week, Date, Month, Year (0 to 99), Automatic Leap Year 
• 32 Wordx8-Bit RAM 
• Seconds, Minutes, Hours Alarm 
• Automatic Power Loss Detection 
• Low Minimum Standby (Timekeeping) Voltage . . . . . 2.2V 
• Selectable Crystal or 50/60Hz Line Input 
• Buffered Clock Output 
• Battery Input Pin that Powers Oscillator and also Connects to VDD Pin When Power Fails 
• Three Independent Interrupt Modes - Alarm - Periodic - Power-Down Sense