Discontinued
ULTRA-COMPACT HIGH PERFORMANCE
SERIAL REAL-TIME CLOCK ICs
1
RS5C317A/B
OUTLINE
The RS5C317A/B are CMOS type real-time clock ICs which are connected to the CPU via three signal lines and
capable of serial transmission of clock and calendar data to the CPU.
The RS5C317A/B can generate various periodic interrupt clock pulses lasting for long period (one month), further
alarm interrupt can be made by days of the week, hours, and minutes. The function of 32kHz clock output and timer
counter for watch-dog-timer are also include. Driving an oscillation circuit at constant voltage, the circuit undergoes
few voltage fluctuations and consequently realizes low current consumption (0.6µA at 3V). It also provides an oscil-
lator halt sensing function for application to data validity at power-on and other occasions. Integrated into a compact
and thin 14pin SSOP (0.65mm pitch), the RS5C317A/B are the optimum choice for equipment requiring small size
and low power consumption.
The RS5C317A and the RS5C317B reads/writes data at falling and rising edge of serial clock respectively.
• Time keeping voltage 1.6V to 6.0V
• Lowest supply current 0.6µA TYP. (1.5µA MAX.) at 3V
• Connection to the CPU via only three pins: CE, SCLK/SCLK and SIO for addressing and data read/write
•A clock counter (counting hours, minutes, and seconds) and a calendar counter (counting leap years, years,
months, days, and days of the week) in BCD code
• Periodic interrupt pulses to the CPU with cycles ranging from one month to 1/1024Hz, with interrupt flags and
interrupt halt
• Alarm interrupt (days of the week, hours, minutes)
• Counter for timer with internal clock
• Oscillator halt sensing to judge internal data validity
• 32kHz clock output with enable switch
• Second digit adjustment by ±30 seconds
• 12-hour or 24-hour time display selectable
• Automatic leap year recognition up to the year 2099
•CMOS logic
• Package: 14pin SSOP (0.65mm pitch)
FEATURES
NO.EA-036-0208
Discontinued
Discontinued
EA-036-101007
Discontinued
RS5C317A/B
2
APPLICATIONS
• Communication equipment (Multi-function telephone, portable telephone, PHS, pager)
• Business machine (Facsimile, portable facsimile)
• Personal computer (Desktop type, notebook type, word processor, PDA, electronic notebook, TV games)
• Audio visual equipment (Portable audio equipment, video camera, camera, digital camera, remote control equip-
ment)
• Home use (Rice cooker, microwave range)
PIN CONFIGURATION
• 14pin SSOP (0.65mm pitch)
CE
1
VDD
SCLK 32KOUT
SIO NC
CLKC OSCIN
ALRM OSCOUT
TMOUT NC
VSS INTR
RS5C317A RS5C317B
14
213
312
411
510
69
78
CE
1
VDD
SCLK 32KOUT
SIO NC
CLKC OSCIN
ALRM OSCOUT
TMOUT NC
VSS INTR
14
213
312
411
510
69
78
BLOCK DIAGRAM
OSC DIV
ADDRESS
DECODER
ADDRESS
REGISTER
TIME COUNTER
(SEC,MIN,HOUR,WEEK,DAY,MONTH,YEAR)
INTERRUPT
CONTROL
SHIFT REGISTER
I/O
CONTROL
OSC
DETECT
OSCIN
OSCOUT
CLKC
32KOUT
32KHz OUTPUT
CONTROL
ALARM REGISTER
(WEEK,MIN,HOUR)
COMPARATOR
SIO
SCLK/SCLK*
CE
INTR
ALRM
TMOUT
*
) RS5C317A: SCLK RS5C317B: SCLK
Discontinued