DekTec DTM-3237 DVB-S2 Receiver - Manual (Page 25)

DTM-3237 – OEM DVB-S2 Receiver with DVB-ASI Output
User Manual
25
4.6 Firmware upgrade
4.6.1 Firmware upgrade - Phases
Updating the firmware of the device consists of five phases:
1. Put the device in firmware upgrade mode by setting Mode (0x85, 0x01) to 1.
2. Erase the current firmware by writing any value to setting Erase (0x85, 0x02).
3. Upload the firmware. The file has to be uploaded in “parts” to setting Programming data (0x85,
0x03), were each part may contain 250 (I 2 C) to 1.000 (LVTTL serial control port) bytes.
4. Verify the uploaded firmware by reading from setting Verify (0x85, 0x04).
5. When the firmware upgrade is successfully completed, the DTM-3237 should be rebooted to
make the upgrade effective, by putting the device in normal operation by setting Mode (0x85,
0x01) to 0.
After the device has been upgraded and rebooted, the DTM-3237 checks the status of the firmware.
In case the firmware isn’t correctly uploaded, the DTM-3237 will stay in firmware upgrade mode. In
this mode the firmware must be uploaded again, starting at the beginning of the firmware file.
When using the USB interface as communication port, care should be taken with entering firmware
upgrade mode or rebooting the DTM-3237, since the USB connection is closed in between. To go
from normal operation to firmware upgrade mode or vice versa, preform these steps:
1. Send the command for switching the mode
2. Close the USB handle within 500ms after sending the mode switch command
3. Wait for the USB interface to disappear and reinitialize, before reopening the USB handle.
The entire firmware upgrade process is implemented in DtmHandler. Please refer to DtmCmd
(appendix C) for an example of how to implement the firmware upgrade using DtmHandler.
4.6.2 Firmware upgrade - Data encoding
To improve the firmware upgrade speed, the following encoding is used for the data part of the
"Programming data" setting (category 0x85, setting 0x03) when using the LVTTL serial control port
and USB interface.
Figure 4. ASCII encoding for firmware upgrade data
For each 7 bits of data one 8-bit ASCII character is sent, where the MSB of the ASCII character is set
to 1 (extended ASCII range). The translation is illustrated in Figure 4.