Using The Internal Oscillator For The System Clock With Reset Mode 0; Using The Internal Oscillator For A 32-Khz Clock With Reset Mode 0 - Texas Instruments OMAP5912 Reference Manual

Figure 10. External CMOS Clock Connections
32kHz Ext. CMOS clk
12, 13, 19.2 MHz
external CMOS clk
Notes: 1) Ball Y13 may be connected to board ground.
5.4

Using the Internal Oscillator for the System Clock with Reset Mode 0

5.5

Using the Internal Oscillator for a 32-kHz Clock with Reset Mode 0

SPRU751A
OMAP5912
VSS
P12 RESET_MODE
P13 CLK32K_IN
CVDDRTC
V13 OSC32K_IN
1
VSS
Y13
VSS
AA13 OSC32K_OUT
Y2 OSC1_IN
N.C. OSC1_OUT
W3
The system clock can be 12MHz, 13MHz, or 19.2MHz. To drive the system
clock with the internal oscillator circuitry, the following hardware connections
are used (see Figure 11). This figure applies to reset mode 0 only.
-
Hardware considerations:
J
The crystal circuit is applied to the OSC1_IN pin (ball Y2) and the
OSC1_OUT pin (ball W3).
-
Software considerations:
J
FUNC_MUX_CTRL_D(2:0) register bits should be 000 to ensure that
ball Y4 is NOT pin multiplexed as the SYS_CLK_IN.
J
Ensure CONF_OSC1_PWRDN_R is 0 in the MOD_CONF_CTRL_1
register so that the oscillator circuit is enabled.
J
Set CONF_OSC1_GZ_R to 0 in MOD_CONF_CTRL_1 (setting this
bit to 1 will also disable the oscillator circuit).
The OMAP5912 32-kHz clock can be driven by an internal oscillator and
crystal. See Figure 11 for the hardware connections of the external 32-kHz
clock. This figure applies to reset mode 0 only.
OMAP5912 Clock Architecture
Clocks 35