RP5C01A Datasheet, PDF (1/10 Pages) RICOH electronics devices division – REAL-TIME CLOCK WITH INTERNAL RAM

RP/RF5C01A
REAL-TIME CLOCK
WITH INTERNAL RAM
NO. EK-086-9804
OUTLINE
The RP/RF5C01A are real-time clocks for microcomputers that can be connected directly to buses of microcom-
puters with such CPUs as the 8085A or Z80 and allow setting or reading of the clock with the same procedures as
for the Read/Write operation for memory.
These products have various features such as clock and calendar counters, alarm functions, and 26 ´ 4bits RAM
which can be backed up by batteries. They can then be used as non-volatile RAM.
FEATURES
• Connected directly to CPU • 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)
• Supports both 12-hour AM/PM clock and 24-hour clock
• All clock data expressed in BCD codes • ±30 second adjustment function
• Backed up by batteries (minimum:2.2V) • Built-in 26 ´ 4bits RAM
• Outputs alarm signals or timing pulse of 16Hz or 1Hz.
• Packages : 18pin DIP (RP5C01A) ; 18pin SOP(RF5C01A)
BLOCK DIAGRAM
1Hz,16Hz,
OSCIN
OSCOUT
OSC
ADJ
CS
CS
RD
1/2¹⁵
S2 S3 S4 S5 S6 S7 S8
43 423 4 2
T-RESET
RD.WR.
MODE01
A-RESET
RD. WR.
MODE 00
ALARM REGISTER
COMPARATOR
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
ALARM ^ALARM
OUTPUT
WR
ADJ
HOLD
S0 ^{S1 S2 S3 S4 S5 S6 S7 S8 S9 SA SB SC}
43 43423424 1442
RD.WR.
MODE10,MODE11
4
CONTROLLER
SD
-SF
SO
ADDRESS
DECODER
SF
BUS
CONTROL
4
SO-SC
INTERNAL
BUS
BUFFER
26´4bits
RAM
A0 A1 A2 A3 D0 D1 D2 D3
1