
201-0000-042 Rev. 1.1, 9/29/2000
3
CHRONTEL
CH7012A
Table 1: Pin Description
64-Pin
LQFP
3
# Pins
Type
Symbol
Description
1
In
VREF
Reference Voltage Input
The VREF pin inputs a reference voltage of DVDDV / 2. The
signal is derived externally through a resistor divider and
decoupling capacitor, and will be used as a reference level for
data, sync and clock inputs.
Horizontal Sync Input / Output
When the SYO bit is low, this pin accepts a horizontal sync
input for use with the input data. The amplitude will be 0 to
DVDDV, and the VREF signal is used as the threshold level.
4
1
In/Out
H
When the SYO bit is high, the device will output a horizontal
sync pulse, 64 pixels wide. The output is driven from the
DVDD. This output is only for use with the TV-Out function.
Vertical Sync Input / Output
When the SYO bit is low, this pin accepts a vertical sync input
for use with the input data. The amplitude will be 0 to DVDDV,
and the VREF signal is used as the threshold level.
5
1
In/Out
V
When the SYO bit is high, the device will output a vertical sync
pulse one line wide. The output is driven from the DVDD
supply. This output is only for use with the TV-Out function.
General Purpose Input - Output[1]
(internal pull-up)
This pin provides a general purpose I/O controlled via the serial
port bus. The internal pull-up will be to the DVDD supply.
General Purpose Input - Output[0]
(internal pull-up)
This pin provides a general purpose I/O controlled via the serial
port bus. This allows an external switch to be used to select
NTSC or PAL at power-up. The internal pull-up will be to the
DVDD supply.
Address Select
(Internal pull-up)
This pin determines the serial port address of the device
(1,1,1,0,1,AS*,AS).
Reset * Input
(Internal pull-up)
When this pin is low, the device is held in the power-on reset
condition. When this pin is high, reset is controlled through the
serial port register.
Serial Data Input / Output
This pin functions as the serial data pin of the serial port
interface, and uses the DVDD supply.
Serial Clock Input
This pin functions as the clock pin of the
serial port
interface,
and uses the DVDD supply.
Current Set Resistor Input
This pin sets the DAC current. A 140 ohm resistor should be
connected between this pin and GND (DAC ground) using
short and wide traces.
7
2
In/Out
GPIO[1]
8
2
In/Out
GPIO[0]
10
1
In
AS
13
1
In
RESET*
14
1
In/Out
SD
15
1
In
SC
35
1
In
ISET