Service manual

ViewSonic Corporation Confidential - Do Not Copy VA903b-1_ VA903m-1
20
TMDS_VDD P 19 (3.3V)
RX0P I 20 Differential Data Input
RX0N I 21 Differential Data Input
TMDS_GND G 22
RXCP I 23 Differential Data Input
RXCN I 24 Differential Data Input
TMDS_GND G 25
TMDS_VDD P 26 (3.3V)
 PWM Interface: 3-2=1 pin (PWM1, PWM2 can be selected from 1 of 3 possible pins.)
Name
I/O
Pin No Description Note
PWM2 / TCON [2] / S
[3]
O 51 PWM2 / TCON [2] / SDIO [3] (1), (2), (3), (5), (8),
PWM2 / TCON [13] /
COUT
O 55 PWM2 / TCON [13] / Crystal out (2), (8), (9)
PWM2 / TCON [12] /
COUT
O 113 PWM2 / TCON [12] / Crystal out (2), (8), (9)
PWM1 / TMDS_TST AIO 9 PWM1/ TMDS_TEST Pin /
Power-on-latch for serial / parallel port
(2), (7), (8)
PWM1 / DDCSDA /
TCON [1] / BBLU [0]
IO 47 PWM1 / DDC serial control I/F data input
/ output / TCON [4]
(1), (2), (3), (5), (8),
PWM1 / DDCSDA2
(HDCP) / TCON [7]
IO 125 PWM1 / DDC serial control I/F data input
/ output / TCON [7]
(1), (2), (3), (5), (8),
PWM0 / REFCLK IO 112 PWM0 / (In / out) test pin for DCLK /
Video8 even-odd signal
(2), (9)
 DDC Channel: 4 pins
Name I/O Pin No Description Note
DDCSCL / TCON [0] /
BBLU [1]
I 46 DDC serial control I/F clock / TCON [0] /
TTL BBLU [1]
(2), (3), (5)
DDCSDA / TCON [1] /
PWM1 / BBLU [0]
IO 47 DDC serial control I/F data input / output
/ TCON [1] / PWM1 / TTL BBLU [0]
(1), (2), (3), (5), (6),
(8)/ 8mA /no slew
DDCSCL2 (HDCP) /
TCON [5]
I 126 DDC serial control I/F clock / TCON [5] (2), (3), (5)
DDCSDA2 (HDCP) /
TCON [7] /PWM1
IO 125 DDC serial control I/F data input / output
/ TCON [7] / PWM1
(1), (2), (3), (5), (6),
(8)/ 8mA /no slew
 Power & Ground: 22 pins
Name
I/O
Pin No Description
3.3V Power P 49,121 VCCIO: 2