pca2125 NXP Semiconductors, pca2125 Datasheet - Page 15

• Manufacturer Part Number: pca2125
• Description: Spi Real Time Clock / Calendar Semiconductors
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA2125_00
Preliminary data sheet
6.6 Timer functions
The countdown timer has four selectable source clocks allowing for countdown periods in
the range from less than 1ms to more than 4hours. There are also two pre-defined timers
which can be used to generate an interrupt once per second or once per minute.
Address registers 01
output.
Table 25.
Table 26.
Table 27.
Bit
7
6
5
4
2
0
3
1
Bit
6:2
7
1 to 0
Bit
7 to 0
Symbol
MI
SI
MSF
TI/TP
TF
TIE
AF
AIE
Symbol
0
TE
CDT
Symbol
n
Control 2 (address 01
Timer control (address 0E
Countdown timer (address 0A
Rev. 00.11 — 30 January 2007
HEX
Value
00 to FF
Value
0
1
0
1
0
1
0
1
0
1
0
1
Value
0
1
0
0
1
1
, 0E
0
1
0
1
HEX
HEX
and 0F
Description
countdown value = n;
CountdownPeriod
Description
Minute interrupt is disabled
Minute interrupt is enabled
Second interrupt is disabled
Second interrupt is enabled
No minute or second interrupt generated
Flag set when minute or second interrupt generated. Flag
must be cleared to release INT.
Interrupt pin follows timer flags
Interrupt pin generates a pulse
No countdown timer interrupt generated
Flag set when countdown timer interrupt generated. Flag must
be cleared to release INT.
No interrupt generated from the countdown timer flag
Interrupt generated when countdown timer flag set
See
See
Description
Reserved for future use.
Countdown timer is disabled
Countdown timer is enabled
4096 Hz countdown timer source clock
64 Hz countdown timer source clock
1 Hz countdown timer source clock
1⁄60 Hz countdown timer source clock
) bits description
HEX
Table
Table
) bits description
HEX
HEX
8.
8.
) bits description
are used to control the timer function and
=
-------------------------------------------------------------- -
SourceClockFrequency
SPI Real time clock / calendar
n
PCA2125
© NXP B.V. 2007. All rights reserved.
Section
Section 6.6.2
Section
Section 6.6.2
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