Timer Data Organization - Epson RTC-4543SA Applications Manual

RTC - 4543 SA/SB

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.
Second
( 0 to 59 )
Minutes
( 0 to 59 )
Hour ( 0 to 23 )
Day of the week
( 1 to 7 )
Day ( 1 to 31 )
Month ( 1 to 12 )
Year ( 0 to 99 )
* 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
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".
V
DD
Detection
pulse
Mode
FDT bit
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".
MSB
FDT s40
* mi40 mi20
* *
* *
TM *
y80 y40
V
DET
0.5 s
s20 s10 s8
mi10 mi8
h20 h10 h8
*
d20 d10 d8
* mo10 mo8
y20 y10 y8
0.5 s
Read
Page - 6
LSB
s4 s2 s1
mi4 mi2 mi1
h4 h2 h1
w4 w2 w1
d4 d2 d1
mo4 mo2 mo1
y4 y2 y1
and GND.
DD
MQ - 252 - 03