User`s guide

Intel
®
StrongARM
®
SA-1110 Microprocessor Development Board User’s Guide 5-3
Analog I/O
5.2 Analog Outputs
The SA-1111 Development Platform’s SA-1111 companion chip provides two Pulse Width
Modulated (PWM) general purpose outputs. These signals are available as test points on the SA-
1111 Development Module and are wired to the 140 pin connectors. The PWM signals are intended
for use in controlling the brightness and contrast of a display system and are not used in the SA-
1110 Development Board but may be used by the GFX graphics boards. A resistor and capacitor
are required to integrate the PWM digital signal to an analog signal. The PWM outputs are
intended as low frequency analog control signals and are limited to less then 1 KHz bandwidth.
The UCB1300 provides an analog audio output for direct drive of a small low power speaker. This
signal is input to the UDA1341 stereo codec which is part of the SA-1110 Development Board
audio mixing function. The UCB1300 also provides a DAC as part of the touch screen interface.
5.3 Touch Screen
The SA-1110 Development Board supports a standard resistive pressure sensitive touch screen.
The UCB1300 directly interfaces to the touch screen mounted over the Sharp 3.9” display. The
touch screen is analog in nature and uses the ten-bit ADC resource in the UCB1300. Refer to the
UCB1300 specification for more information about touch screens.