SNLA308A April 2019 – October 2020 DS90UB941AS-Q1 , DS90UH941AS-Q1
The deserializer includes oscillator divider control to support additional back-channel frequencies other than the default 5-Mbps speed. The engineer can configure the OSC_DIVIDER controls in register 0x32, as well as the BC_FREQ_SELECT control in register 0x23[2], to control the oscillator divider. The supported frequencies are 100 MHz/N or 50 MHz/N. Table 11-3 lists the back-channel frequency settings.
The non-default settings of the OSC_DIVIDER are for evaluation purposes only, as they may cause other functions in the device to operate at unexpected frequencies. Note that if BC_HIGH_SPEED is set to a 1, only even values of N are supported.
OSC_Divider | DIV Ratio N | BC_FREQ_SELECT (Mbps) 0 | BC_FREQ_SELECT (Mbps) 1 | BC_HIGH_SPEED (Mbps) 1 |
---|---|---|---|---|
0x0 | 1 | 50 | 100 | N/A |
0x1 | 2 | 25 | 50 | 100 |
0x2 | 3 | 16.67 | 33.33 | N/A |
0x3 | 4 | 12.5 | 25 | 50 |
0x4 | 5 | 10 | 20 | N/A |
0x5 | 6 | 8.33 | 16.67 | 33 |
0x6 | 7 | 7.14 | 14.28 | N/A |
0x7 | 8 | 6.25 | 12.5 | 25 |
0x8 | 9 | 5.55 | 11.11 | N/A |
0x9 | 10 | 5 (default) | 10 | 20 |
0xA | 11 | 4.55 | 9.1 | N/A |
0xB | 12 | 4.17 | 8.33 | 16.67 |
0xC | 13 | 3.85 | 7.69 | N/A |
0xD | 14 | 3.57 | 7.14 | 14.28 |
0xE | 15 | 3.33 | 6.67 | N/A |
0xF | 16 | 3.125 | 6.25 | 12.5 |