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Real Time Clock
RTC Implementation
Increment of Nanoseconds Field
Figure 8-2 illustrates the implementation used to create the RTC nanoseconds field. This is performed by the use of an implementation specific 20-bit sub-nanoseconds field as illustrated. The nanoseconds and sub-nanoseconds fields can be considered to be concatenated together.
All RTC logic within the core is synchronous to the RTC Reference Clock, rtc_clk.
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Step 1
fill with zero’s
RTC Increment Value (26 bits)
(written by processor)
controlled frequency RTC
Step 2
RTC Nano Seconds Offset (30 bits) (written by processor)
Synchronised RTC
Figure 8-2: Increment of Sub-nanoseconds and Nanoseconds Field
Ethernet AVB Endpoint User Guide | www.xilinx.com | 77 |
UG492 July 23, 2010