3-WIRE REAL-TIME CLOCK
S-35190A
Rev.2.4_00
3. Status register 2
Status register 2 is a 1-byte register that is used to display and set various modes. The bit configuration is shown below.
B6
B5
B4
B3
B2
B1
B0
B7
SC2
R/W
SC3
R/W
INT2AE
R/W
TEST
R/W
INT1FE
R/W
INT1AE
R/W
32kE
R/W
INT1ME
R/W
R/W: Read/Write
Figure 16 Status Register 2
B0 : TEST
This is a test flag for SII. Be sure to set this flag to “0” in use. If this flag is set to “1”, be sure to initialize to set “0”.
B1 : INT2AE
This is an enable bit for alarm 2 interrupt. When this bit is “0”, alarm 2 interrupt is disabled. When it is “1”, it is enabled.
To use alarm 2 interrupt, access the INT register 2 after enabling this flag.
Caution Note that alarm 2 interrupt is output from the INT pin regardless of the settings in flags B4 to B7.
B2 : SC3, B3 : SC2
These are 2-bit SRAM type registers that can be freely set by users.
B4 : 32kE, B5 : INT1AE, B6 : INT1ME, B7 : INT1FE
These bits are used to select the output mode for the INT pin. Table 10 shows how to select the mode. To use alarm
1 interrupt, access the INT register 1 after setting the alarm 1 interrupt mode.
Table 10 Output Modes for INT Pin
32kE
INT1AE
0
INT1ME
INT1FE
INT Pin Output Mode
0
0
0
0
0
0
1
0
0
1
1
0
1
0
1
0
1
0
1
No interrupt
*1
−
−
Output of user-set frequency
Per-minute edge interrupt
Minute-periodical interrupt 1 (50% duty)
Alarm 1 interrupt
Minute-periodical interrupt 2
32.768 kHz output
*1
0
1
1
*1
*1
*1
−
−
−
*1. Don’t care (Both of 0 and 1 are acceptable).
14
Seiko Instruments Inc.
SII [ SEIKO INSTRUMENTS INC ]
