Using The Internal Oscillator For The System Clock With Reset Mode 1; Using The Internal Oscillator For A 32-Khz Clock With Reset Mode 1 - Texas Instruments OMAP5912 Reference Manual

OMAP5912 Clock Architecture
5.8

Using the Internal Oscillator for the System Clock with Reset Mode 1

5.9

Using the Internal Oscillator for a 32-kHz Clock with Reset Mode 1

Figure 13. 32-kHz Oscillator Clock Connections (Reset Mode 1)
Notes: 1) Ball Y13 MUST NOT be connected to board ground (VSS). Please see the OMAP5912 Data Manual (SWPS012)
for more details on clock connections.
38 Clocks
The OMAP5912 system clock cannot be driven by the internal oscillator when
reset mode is 1. The internal oscillator is automatically placed in low-power
mode when reset mode is 1.
The OMAP5912 32-kHz clock can be driven by an internal oscillator and
crystal. See Figure 13 for the hardware connections of the external 32-kHz
clock. This figure applies to reset mode 1 only.
-
Hardware considerations:
J
The crystal circuit is applied to the OSC32K_IN pin (ball V13) and the
OSC32K_OUT pin (ball AA13).
J
CLK32K_IN (ball P13) must be tied low directly or with a pulldown
resistor. Any activity on this pin will corrupt the 32-kHz clock.
VDD
VSS
32kHz Crystal
osc. circuit
19.2 MHz external
clk only
See Figure 14 for a summary of the 32-kHz and system clock internal
connections.
OMAP5912
P12 RESET_MODE
P13 CLK32K_IN
V13 OSC32K_IN
Y13 1
AA13 OSC32K_OUT
Y4 SYS_CLK_IN
SPRU751A