Epson RTC-4543SB - Manual (Page 9)

RTC - 4543 SA/SB
Page - 6 MQ - 252 - 03
6. Timer Data Organization
•
The counter data is BCD code.
•
The timer automatically adjusts for different month lengths and for leap year.
•
The time is indicated in 24-hour format.
•
Writes and reads are both performed on an LSB-first basis.
MSB LSB
Second
( 0 to 59 )
FDT s40 s20 s10 s8 s4 s2 s1
Minutes
( 0 to 59 )
* mi40 mi20 mi10 mi8 mi4 mi2 mi1
Hour ( 0 to 23 )
* * h20 h10 h8 h4 h2 h1
Day of the week
( 1 to 7 )
* w4 w2 w1
Day ( 1 to 31 )
* * d20 d10 d8 d4 d2 d1
Month ( 1 to 12 )
TM * * mo10 mo8 mo4 mo2 mo1
Year ( 0 to 99 )
y80 y40 y20 y10 y8 y4 y2 y1
* bits: Any data may be written to these bits.
•
FDT bit: Supply voltage detection bit
•
This bit is set to “1” when voltage of 1.7
±
0.3 V or less is detected between V DD and GND.
•
The FDT bit is cleared if all of the digits up to the year digits are read.
•
Although this bit can be both read and written, normally set this bit to “0”.
Detection
pulse
V DD
Mode
FDT bit
V DET
0.5 s
Read
0.5 s
The supply voltage detection circuit monitors the supply voltage once every 0.5 seconds;
if the supply voltage is lower than the detection voltage value, the FDT bit is set to “1”.
•
TM bit: This is a test bit for SEIKO-EPSON’s use. Always set this bit to “0”.