Micro Crystal
Ultra Small Real-Time Clock Module with I
2
C-Bus Interface
RV-8263-C7
January 2019
20/61
Rev. 1.0
TIMER REGISTERS
3.5.
10h
– Timer Value
This register holds the current value of the Countdown Timer. It may be loaded with the desired starting value when
the Countdown Timer is stopped.
Address
Function
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
10h
Timer Value
128
64
32
16
8
4
2
1
Reset
0
0
0
0
0
0
0
0
Bit
Symbol
Value
Description
7:0
Timer Value
00h to
FFh
Countdown Timer Value (see COUNTDOWN TIMER FUNCTION)
Countdown Period in seconds:
Countdown Period =
Timer Value
Timer Clock Frequency
11h
– Timer Mode
This register controls the Countdown Timer function.
Address
Function
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
11h
Timer Mode
X
X
X
TD
TE
TIE
TI_TP
Reset
0
0
0
1
1
0
0
0
Bit
Symbol
Value
Description
7:5
X
0
Unused
4:3
TD
Timer Clock Frequency (see COUNTDOWN TIMER FUNCTION)
(1)
00
4.096 kHz
01
64 Hz
(2)
10
1 Hz
(2)
11
1/60 Hz
– Default value
(2)
2
TE
Timer Enable
0
Disabled
– Default value
1
Enabled
1
TIE
Timer Interrupt Enable
0
No interrupt generated from timer.
– Default value
1
Interrupt generated from timer.
0
TI_TP
Timer Interrupt Mode.
How the setting of TI_TP and the Timer Flag TF can affect the
INT
̅̅̅̅̅
pulse generation is
explained in sections COUNTDOWN TIMER FUNCTION and MINUTE AND HALF
MINUTE INTERRUPT FUNCTION.
0
Interval Mode. Interrupt follows Timer Flag TF.
– Default value
1
Pulse Mode. Interrupt generates a pulse.
(1)
When not in use, the TD field is recommended to
be set to 11 (1⁄60 Hz) for power saving.
(2)
Time periods can be affected by compensation pulses (64 Hz only in MODE = 1), (see FREQUENCY OFFSET COMPENSATION).
