rs5c62 RICOH Co.,Ltd., rs5c62 Datasheet - Page 24

• Manufacturer Part Number: rs5c62
• Description: Real-time Clock
• Manufacturer: RICOH Co.,Ltd.

20
RP/RF/RS5C62
4. Adjustment of Oscillation Frequencies
4.1 Measurement of Oscillation Frequency
surement is affected by and cannot therefore be obtained with accuracy by the OSCIN pin input and the OSCOUT
pin output, which are directly measured by such means as a probe.
The oscillation frequency can be measured by using the INTR pin output (a cyclic interrupt). Note that its mea-
OSCOUT
OSCIN
INTR
V
DD
Control register 3
Control register 1
Control register 2
selection register
Read frequency counter
Interrupt cycle
Power-on from 0V
C
C
G
D
Ch
1h
0h
5h
*
*
*
3
2
1
Frequency
counter
*
*
*
*
*
V
4
5
6
7
8
DD
*
*
*
*
*
*
*
*
1) Use a frequency counter with 6 or more readout digits in order to ensure
2) Pull up the INTR pin to the V
3) Connect either one end of the oscillatory capacitors C
4) Set both the TSTA and TSTB bits to “1” in the control register 3 to disable
5) Set the ALEN bit to “0” and the BANK bit to “1” in the control register 1 to
6) Set both the CTFG and ALFG bits to “0” in the control register 2 to disable
7) Set a cyclic interrupt to 1Hz (or any other cycle) in the pulse mode.
8) An error of ±1ppm for every 1Hz amounts to a time lag of approximately
pin.
an accuracy on the order of ±1ppm.
the test circuit.
disable an alarm interrupt.
an alarm interrupt and a cyclic interrupt.
2.6 seconds per month.
[Example of monthly time lag calculation given an error of ±1ppm for
every 1Hz.
±1ppm x 60 seconds x 60 minutes x 24 hours x 30 days = 2.592
= approx. 2.6 seconds per month ]
DD
and set the CE pin to high.
G
and C
D
to the V
DD