Table 3-61 describes the write parameters.
Table 3-61 Write ParametersParameter Bytes | Description |
---|
Byte 1 | Red LED current parameter (LSByte) |
Byte 2 | Red LED current parameter (MSByte) |
Byte 3 | Green LED current parameter (LSByte) |
Byte 4 | Green LED current parameter (MSByte) |
Byte 5 | Blue LED current parameter (LSByte) |
Byte 6 | Blue LED current parameter (MSByte) |
When an all-white image is displayed,
this command allows the system white point to be adjusted while establishing the
total LED power whether the CAIC algorithm is enabled or disabled.
The parameters specified by this
command have a resolution of 10 bits, and are defined by the appropriate DLPA200x
specification.
When the CAIC algorithm is disabled,
this command directly sets the LED currents (the R, G, and B values provided are
sent directly to the DLPA200x device) regardless of the image being displayed.
When the CAIC algorithm is enabled:
- This command directly sets
the LED currents when an all-white image is displayed. If the image is
changed from an all-white image, depending on the image the CAIC algorithm
may alter one or more of the LED currents from those specified by this
command, and the total LED power may drop. The Read CAIC RGB LED
Current command can read the actual LED currents for the image
currently displayed.
- In the case of an all-white
image, the values read by the Read CAIC RGB LED Current command
closely match, but may not exactly match, those requested using the Write
RGB LED Current command. For an all-white image, the Read CAIC
RGB LED Current command gives currents within +/-4 DLPA200x device
current steps for each LED color relative to those requested by the Write
RGB LED Current command.
- When the Write RGB LED
Current command changes the LED currents, the LED current for any
color must not be changed by more than +/-25% from the nominal current used
for that color when the CAIC LUTs were created. No LED current can be set to
a current value beyond the maximum value supported in the CAIC
intensity-to-current LUT for the corresponding color.
- The maximum total LED power
for any displayed image occurs for an all-white image, since the CAIC
algorithm requests the CAIC LED maximum available power. The maximum
available LED power for the CAIC is controlled by the Write RGB LED
Current command, as this command controls currents for an all-white
image. After the currents are adjusted, the Read CAIC LED Max Available
Power command is used to see the maximum power in watts derived from
the CAIC.