To perform a Write operation on the DLPC900, the host must assemble a sequence of bytes that corresponds to the command being used. The following Table 1-7 shows an example on how to set the curtain color intensity of each color to 511.
Table 1-7 Write Operation Example (1)REPORT ID BYTE | FLAG BYTE | SEQUENCE BYTE | LENGTH (2) | USB COMMAND (2) | DATA (2) |
---|
0x00 | 0x00 | 0x12 | 0x08 0x00 | 0x00 0x11 | 0xFF 0x01 0xFF 0x01 0xFF 0x01 |
(1) All values shown are in HEX notation.
(2) LSB precedes the MSB for each parameter.
- Report ID byte: Always set to 0.
- Flag byte. Where:
- Bits 2:0 are set to 0x00 for regular DLPC900
operation.
- Bit 6 is set to 0x00 to indicate the host does
not want a reply from the device. This bit is set
to 0x01 only if a reply is needed, which is
usually not required.
- Bit 7 is set to 0x00 to indicate a write
transaction.
- Sequence byte: The sequence byte can be a rolling
counter and is used primarily when the host wants a response from the
DLPC900. Normally during a write operation, the DLPC900 does not respond;
however, the host can continue to increment the sequence byte for the next
command operation.
- Length: Two bytes in length, this denotes the
number of data bytes in the sequence but excludes the number of bytes in
steps 1 through 4. The length denotes the total number of bytes sent in
steps 5 (command bytes) and 6 (data bytes).
- USB Command: Two byte USB command.
- Data: The data appropriate to the command.