PT7C43190 Datasheet, PDF (13/32 Pages) Pericom Semiconductor Corporation – Real-time Clock Module

|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Hz Clock Output and Second-counter
3.5. Clock Correction Register
The clock correction register is a 1-byte register that is used to correct advance / delay of the clock. When not using this function,
set this register to "00h". Regarding the register values, refer to "Function to Clock Correction".
B7
B6
B5
B4
B3
B2
B1
B0
V0
V1
V2
V3
V4
V5
V6
V7
R/W
R/W
R/W
R/W
R/W
R/W
3.6. Free Register
This free register is a 1-byte SRAM type register that can be set freely by users.
B7
B6
B5
B4
B3
B2
V0
V1
V2
V3
V4
V5
R/W
R/W
R/W : Read/Write
B1
B0
V6
V7
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W : Read/Write
4. Power-on Detection Circuit and Register Status
The power-on detection circuit operates by power-on the RTC, as a result each register is cleared; each register is set as follows.
Real-time data register: 00 (Y), 01 (M), 01 (D), 0 (day of the week), 00 (H), 00 (M), 00 (S)
Status register 1: "01h"
Status register 2: "80h"
INT register 1: "80h"
INT register 2: "00h"
Clock correction register: "00h"
Free register: "00h"
"1" is set in the POC flag (B0 in the status register 1) to indicate that power has been applied. To correct the oscillation frequency,
the status register 2 goes in the mode the output of user-set frequency, so that 1 Hz clock pulse is output from the INT pin. When
"1" is set in the POC flag, be sure to initialize. The POC flag is set to "0" due to initialization so that the output of user-set
frequency mode is cleared. (Refer to "Register Status After Initialization".)
For the regular operation of power-on detection circuit, as seen in below Figure, the period to power-up the RTC is that the
voltage reaches 1.3 V within 10 ms after setting the IC’s power supply voltage at 0 V. When the power-on detection
circuit is not working normally is; the POC flag (B0 in the status register) is not in "1", or 1 Hz is not output from the INT pin.
In this case, power-on the RTC once again because the internal data may be in the indefinite status.
Moreover, regarding the processing right after power-on, refer to "Flowchart of Initialization and Example of Real-time Data
Set-up".
2015-09-0015
PT0274-7 10/16/15
13