STV2050A STMicroelectronics, STV2050A Datasheet - Page 59

• Manufacturer Part Number: STV2050A
• Description: IC DGTL CONVERGENCE PROC 80-PQFP
• Manufacturer: STMicroelectronics
• Type: Videor

Specifications of STV2050A

• Applications: HDTV
• Mounting Type: Surface Mount
• Package / Case: 80-MQFP, 80-PQFP
• Case: QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12 OPTICAL LOOP
12.1 PRINCIPAL OF OPERATION
Figure 33. Optical Loop
The STV2050A can deliver a dedicated video pattern known as an “auto-alignment pattern”.
This pattern is rectangular-shaped, and its width, height and brightness are programmable.
Refer to
The presence or absence of this pattern can be detected by optical sensors; for example, by
a camera in the production line, or photo detector diodes placed around the Projection screen.
The STV2050A can read the status of the sensors within a programmable time limit. The re-
sults are made available in the E5 register, allowing the MCU to run a routine for making the
necessary corrections.
Two pins are dedicated to the optical loop:
– The OPPT pin is a port normally used as an output, and can deliver a logical electrical signal
– The OPTI pin is an input port for logical 0 or 1 levels. This port is sampled by the STV2050A
12.2 OPTT SENSOR PORT CONTROL
The OPTT sensor port can be programmed as an input or as an output by the ODS in the E5
register.
with a programmable time limit.
to indicate the status of the sensor.
Section 7.6 "Auto-alignment Pattern" on page
µP
ODS
I²C
STV 2050D
STV2050A
Dynamic
Gain
Static
Offset
timing
H/V
grid
0 = OPTT is an input
1 = OPTT is an output
RGB
H
V
OPTT
OPTI
40.
sensor
STV2050A - OPTICAL LOOP
59/83