RICOH RS5C314 Datasheet
ULTRA-COMPACT
REAL-TIME CLOCK IC
RS5C314
EK-082-9908
1
OUTLINE
The RS5C314 is a CMOS type real-time clock which is connected to the CPU via three signal lines and capable of
serial transmission of clock and calendar data to the CPU. The RS5C314 can generate various interrupt clock pulses
lasting for long periods (one month). Driving an oscillation circuit at constant voltage, the circuit undergoes few
voltage fluctuations and consequently realizes low current consumption (TYP. 0.7µA at 3 V). It also provides an
oscillator halt sensing function for application to data validity at power-on and other occasions. Integrated into an
ultra-compact and ultra-thin 8pin SSOP (0.65mm pitch), the RS5C314 is the optimum choice for equipment requiring
small size and low power consumption.
There is RS5C313 reversing the logic of serial clock for series goods.
• Time Keeping Supply Voltage: 1.6 to 6.0 V • Operating Supply Voltage: 2.7 to 6.0 V
• Low Current Consumption: TYP. 0.7µA (MAX. of 1.5µA) at 3V
• Connection to the CPU via only three pins: CE, SCLK, and SIO (for addressing and data read and write opera-
tions)
• A clock counter (counting hours, minutes, and seconds) and a calendar counter (counting leap years, years,
months, days, and days of the week) in binary-coded decimal (BCD) code
• Generation of interrupt pulses to the CPU with cycles ranging from 1 month to 1/1024 Hz, interrupt flags, and
interrupt halt
• Software-based alarming through clock-interlocked interrupt operation
• Oscillator halt sensing to judge internal data validity
• 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: 8pin SSOP (0.65mm pitch)
FEATURES
PIN CONFIGURATION
1
2
3
4
CE
SCLK
SIO
VSS
8
7
6
5
VDD
OSCIN
OSCOUT
INTR
• 8pin SSOP
RS5C314
2
A DIFFERENCE WITH RS5C313
The logic of serial clock is point that it become that RS5C313 reverses RS5C314 with SCLK for SCLK and differ-
ence point of RS5C314 and RS5C313, describe is the master of by it being different in the following 3 items
(Give RS5C313 application manual absolutely reference in electric characteristic / the thing AC/DC require-
ments rating / recommendation gesture a maximum.)
BLOCK DIAGRAM
SEC. MIN. HOUR WEEK DAY
MONTH
YEAR
OSCIN
OSCOUT
VDD
VSS
INTR
OSC DIV
OSC
DETECT
VOLTAGE
REGULATOR
ADDRESS
DECODER
INTERRUPT
CONTROL
SHIFT REGISTER
I/O
CONTROL
ADDRESS
REGISTER
SIO
SCLK
CE
TIME COUNTER
1.
Timing Chart
Input/output conditions
V
IH = 0.8 × VDD
VIL = 0.2 × VDD
VOH = 0.8 × VDD
VOL = 0.2 × VDD
tSCK
tCES
tCKS
tCEH
tCR
tRE
tRZ
tCKL tCKH
tRR
Read Data
Write Data
t
DS tDH
CE
SCLK
SIORead cycle
Write cycle
SIO
*
) The ability that is fair in “H” or “L” slanted line department
Loading...