XTAL
32.768
kHz
C2
C1
RTC_XI
RTC_XO
RTC_VSS
32K
OSC
Real-
Time
Clock
(RTC)
Module
Isolated RTC
Power Domain
CV
DD
RTC_CV
DD
RTC
Power
Source
250
TMS320C6748
SPRS590G –JUNE 2009–REVISED JANUARY 2017
www.ti.com
Submit Documentation Feedback
Product Folder Links: TMS320C6748
Peripheral Information and Electrical Specifications Copyright © 2009–2017, Texas Instruments Incorporated
6.31.1 Clock Source
The clock reference for the RTC is an external 32.768-kHz crystal or an external clock source of the same
frequency. The RTC also has a separate power supply that is isolated from the rest of the system. When
the CPU and other peripherals are without power, the RTC can remain powered to preserve the current
time and calendar information. Even if the RTC is not used, it must remain powered when the rest of the
device is powered.
The source for the RTC reference clock may be provided by a crystal or by an external clock source. The
RTC has an internal oscillator buffer to support direct operation with a crystal. The crystal is connected
between pins RTC_XI and RTC_XO. RTC_XI is the input to the on-chip oscillator and RTC_XO is the
output from the oscillator back to the crystal.
An external 32.768-kHz clock source may be used instead of a crystal. In such a case, the clock source is
connected to RTC_XI, and RTC_XO is left unconnected.
If the RTC is not used, the RTC_XI pin should be held either low or high, RTC_XO should be left
unconnected, RTC_CVDD should be connected to the device CVDD, and RTC_VSS should remain
grounded.
Figure 6-85. Clock Source
To Next Page
Loading...
Need help?
General
