Phytec phyCORE-LPC2292/94, Hardware Manual

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phyCORE-LPC2292/94
62
©
PHYTEC Messtechnik GmbH 2006 L-658e_5
10 Real-Time Clock RTC-8564 (U604)
For real-time or time-driven applications, the phyCORE-LPC2292/94
is equipped with a RTC-8564 Real-Time Clock at U604. This RTC
device provides the following features:
•
Serial input/output bus (I
2
C), address 0xA2
•
Power consumption
Bus active (400 kHz): < 1 mA
Bus inactive, CLKOUT inactive: < 1
μ
A
•
Clock function with four year calendar
•
Century bit for year 2000-compliance
•
Universal timer with alarm and overflow indication
•
24-hour format
•
Automatic word address incrementing
•
Programmable alarm, timer and interrupt functions
The Real-Time Clock is programmed via the I
2
C bus (address 0xA2 /
0xA3). Since the LPC2292/94 is equipped with an internal I
2
C
controller, the I
2
C protocol is processed very effective without
extensive processor action.
The Real-Time Clock also provides an interrupt output that extends to
the /IRQRTC signal X1D33. An interrupt occurs in the event of a
clock alarm, timer alarm, timer overflow and event counter alarm. It
has to be cleared by software. With the interrupt function, the
Real-Time Clock can be utilized in various applications.
If the RTC interrupt is to be used as a software interrupt via a
corresponding interrupt input of the processor, the signal /IRQRTC
must be connected externally with a processor interrupt input.
For more information on the features of the RTC-8564, refer to the
corresponding Data Sheet.
Note:
After connection of the supply voltage the Real-Time Clock generates
no interrupt. The RTC must first be initialized ( see RTC Data Sheet
for more information ).