OMAP4460 Pandaboard ES
System Reference Manual
Revision 0.1
September 29, 2011
DOC-21054
Page 21 of 82
CLK32KG: a gated 32.768 clock connected to the SLOW_CLK input of the LS Research
module. This clock will be off by default at reset, and must be enabled by software.
2.6
TWL6040 Audio Companion IC
The TWL6040 device is a small (6 x 6 mm, 0.5mm pitch) 120 ball PBGA that provides many functions,
primarily audio, used on the Platform. Shown below is a feature list of the major functions/interfaces
provided by the TWL6040 device.
A audio management system
o
PDM Interface for Audio and control
o
Analog Microphone Interface
o
Headset – speaker (32 ohm) and microphone
o
Earpiece Output
o
Aux Output
o
Hands-free 8 ohm driver
o
Dual Vibrator
Misc Control
o
GPO
o
I2C (high speed)
o
Power on/off
Power
o
Internal LDOs
o
Internal negative charge pump
2.7
SYSBOOT Configuration
The OMAP4460 Processor has eight SYSBOOT inputs. These inputs are sampled after a board reset, and
determine the booting and operating mode of the OMAP4460 Processor. The upper two inputs
(SYSBOOT[7:6]) control the clocking modes of the part (i.e. enabling/disabling the internal oscillator to
allow using a crystal input or oscillator). They are currently set to “11” and should not be changed.
The lower six inputs, SYSBOOT[5:0] determine the type and order of memory or peripheral booting.
SYSBOOT[5] determines whether memory or peripheral booting is preferred. The SYSBOOT
definitions may be found in the OMAP4460 TRM, but are included here for convenience. See Table 2 on
page 24 for the SYSBOOT definitions for peripheral preferred booting, and Table 3 on page 25 for
memory preferred booting SYSBOOT definitions. The shaded row(s) in Table 2 are the default
configuration of the Pandaboard ES, depending on the setting of SW1.
If it is desired to change the SYSBOOT configuration, resistors may be added or removed from the
SYSBOOT[5:0] lines (except for SYSBOOT3, which may be changed by changing the position of switch
SW1). The SYSBOOT[5:0] lines have weak internal pull-down resistors inside the OMAP4460, so
removing the onboard resistor will result in the line being sampled as a ‘0’ at reset, and installing a 3.3K
electronic components distributor
