Freescale Semiconductor MPC8313E PowerQUICC II Pro Family Reference Manual page 245

register (RTEVR) is used to report the interrupt source. The RTC counter is initialized by software and can
be disabled if needed.
Figure 5-24 shows the high level RTC block diagram.
Figure 5-24. Real Time Clock Module High Level Block Diagram
5.5.2 RTC Features
The key features of the RTC include the following:
• Maintains a one-second count, unique over a period of thousand of years
• 32-bit RTC counter can be initialized by software to specific initial count value
• Provides an alarm function with programmable and maskable alarm interrupt
• Provides programmable and maskable every second interrupt
• Uses two possible clock sources: the CSB bus clock or an external RTC clock
• RTC function can be disabled if needed
5.5.3 RTC Modes of Operation
The RTC unit can operate in the following modes:
• RTC enable/disable mode
• RTC every-second interrupt enable/disable mode
• RTC alarm interrupt enable/disable mode
• RTC internal/external input clock mode
5.5.4 RTC External Signal Description
This section provides an overview and detailed descriptions of the RTC signals.
There is one distinct external RTC clock input signal, defined in
Name Port
RTC_CLK RTC_CLK
Table 5-38 provides a detailed description of the external RTC signal.
MPC8313E PowerQUICC™ II Pro Integrated Processor Family Reference Manual, Rev. 2
Freescale Semiconductor
RTC Input
Clock
CSB Bus
Clock
Register Interface
Table 5-37. RTC Signal Properties
Real time clock input.
Second
Interrupt
Real Time
Clock Module
Alarm
Interrupt
Table
Function
System Configuration
5-37.
I/O Reset
I N/A
Pull Up
—
5-37