Vizio L37 Service Manual page 42

5. Microprocessor interface
When power is supplied and power key is pressed then the rest circuit lets Reset to low
state that will reset the MTK8205 to initial state. After that the Reset will transits to high
state and the MTK8205 start to work that microprocessor executes the programs and
configures the internal registers. The execution speed of CPU is 133 MHz.
a. The I/O ports are configured as follows：
Pin name Function
AF26 VGASCL
AE26 VGASDA
AB23 REQUEST# Input / Output
AB24 READY#
AD22 SCL
AC22 SDA
OBO0 SOURCE
OBO1 MENU
OBO2 UP
OBO3 DOWN
OBO4 RIGHT
OBO5 LEFT
OBO6 AUTO
OBO7 POWER
OGO5 LED
AF24
AE23 GPIO
AD23 PWM0
AC23 PWM1
AF6 ORO6
AE20 UP1_4
AF20 UP1_3
AE19` UP1_2
AE21 UP3_0
AD21 UP3_1
CONFIDENTIAL – DO NOT COPY
Type
Input / Output
Input / Output
Input / Output
Input / Output
Input / Output
Input
Input
Input
Input
Input
Input
Input
Input
Output
IR Input / Output
Output
Output
Output
Output
Input
Output
Output
Output
Output
Description
Key detection
Key detection
Key detection
Key detection
Key detection
Key detection
Key detection
Key detection
Power on of TV board and panel
Backlight Adjustmance
Select mute
RCA out mute
S-video Detect
HDMI SCDT
YCBCRSEL
Backlight ON/OFF
HDMI CAB
Page 8-6
File No. SG-0176