RP5C15 Datasheet, PDF (1/12 Pages) RICOH electronics devices division – REAL-TIME CLOCK

RP/RF/RJ5C15
REAL-TIME CLOCK
NO. EK-086-9908
OUTLINE
The RP/RF/RJ5C15 are real-time clocks for microcomputers that can be connected directly to data buses of
16bit CPUs, such as the 8086, Z8000, and 68000, and of 8bit CPUs, such as the 8085A, Z80, 6809, and 6502. They
allow setting or reading of the clock with the same procedures as for the Read/Write operation for memory.
These products have various features including clock, calendar and alarm functions and can be backed up by
batteries.
FEATURES
• Connected directly to CPU enabling fast access. • 4bit bidirectional data bus : D0 - D3
• 4bit address input : A0 - A3
• Built-in clock counter (hour, minute, second) and calendar counter (leap year, year, month, day, day-of-the-week)
• All clock data expressed in BCD codes
• Backed up by batteries (minimum : 2.0V)
• Selectable basic clock frequency : 16kHz, 1kHz, 128Hz, 16Hz, 1Hz, 1/60Hz.
• Outputs alarm signals or timing pulse of 16Hz or 1Hz. • CMOS technology
• Supply voltage : Single power supply of +5V
• Packages RP5C15......18pin DIP
RF5C15......18pin SOP
RJ5C15......28pin PLCC
BLOCK DIAGRAM
OSCIN
OSCOUT
CS
CS
RD
WR
OSC
16kHz, 1kHz, 128Hz, 16Hz, 1Hz, 1/60Hz
1/2¹⁵
S2 S3 S4 S5 S6 S7 S8
43 423 4 2
T.RESET
RD.WR.
BANK 1
ALARM REGISTER
ALARM
RESET
COMPARATOR
ALARM
RD. WR.
BANK 0. RD. WR.
1Hz, 16Hz
ALARM
OUTPUT
ALARM
CLOCK
HOLD
SECONDS MINUTES HOURS
DAYS MONTHS YEARS
1_/10 1_/6 1_/10 1_/6 1_/12 1_/24 1_/7 1_/28-1_/31 1_/12 1_/10 1_/10 1_/4
ADJ
HOLD
S1 S2 S3 S4 S5 S6 S7 S8 S9 SA SB SC
4 ^S0 3 4 3 4 2 3 4 2 4 1 4 4 2
3
4
CONTROLLER
SD
-SF
SO
ADDRESS
DECODER
SF
BUS
CONTROL
CLOCK
SELECT
CLOCK
OUTPUT
CLKOUT
A0 A1 A2 A3 D0 D1 D2 D3
1