I 2 S A u d i o I / O C a r d
Rev. 0.1
7
4.3. Potentiometer (R68)
The potentiometer connects to the ADC_IN0 signal and can be used for volume control. The MCU card must
implement firmware to modulate the volume as the potentiometer value changes.
4.4. Switches and LEDs
The I/O card has two push-button switches (S2 and S4) and two LEDs (D1 and D2). The switches are normally
open and pull the signal voltage to ground when pressed. Table 2 shows the UDP signal connections for these
switches and LEDs.
4.5. Co-processor MCU (U7)
The I/O card has a C8051F380 co-processor MCU (U7) that controls the Graphic QVGA LCD (LCD1) and reads
the five-direction joystick switch (S1). This co-processor enables stand-alone demos that do not require a PC when
connected with an MCU card through the UDP motherboard.
4.5.1. Graphic QVGA LCD (LCD1)
The graphic QVGA LCD (LCD1) connects to the co-processor C8051F380 MCU EMIF through the J6 connector.
This color LCD (SDT022ATFT by Displaytech Ltd.) has a resolution of 320 x 240 resolution. The power
consumption of the LCD can be measured using the J8 header. Table 3 show the co-processor port pin
connections to the LCD.
Table 2. Switch and LED Connections
SW or LED
UDP Signal
Push-Button Switch (S4)
GPIO00
Push-Button Switch (S2)
GPIO01
Blue LED (D2)
PWR_3.3_BULK
Red LED (D1)
GPIO02
Table 3. Joystick Switch Connections
LCD Signal
Co-processor Pin or
UDP Signal
IM0
PWR_3.3_BULK
IM3
LEDA
VCC
DB10
P4.0
DB11
P4.1
DB12
P4.2
DB13
P4.3
DB14
P4.4
DB15
P4.5
DB16
P4.6
DB17
P4.7
RD
P1.6
RS/SCL
P3.0
WR
P1.7
LCD_RESET
P1.1
