Dear Technical Support Team,
I have been debugging for CDR unlocked issue with DS110DF410.
Questions:
1.) Could you share the appropriate setting for 11.0957Gbps?
According to 8.4.4 Standards-Based Modes, the procedure is as follow.
I'd like to know correct register setting each steps for not Standards-Based Modes such as 11.0957Gbps.
Especially register from 0x60 to 0x63(PPM count as NPPM = 11.0957 × 1280 = 14202.496?) and register 0x2f(table 2).
1. Select the desired channel of the DS110DF410 by writing the appropriate value to register 0xff.
2. Set bits 5:4 of register 0x36 to a value of 2'b11 as described above to enable the 25 MHz reference clock.
3. Write registers 0x2f, and 0x36 with the correct values.
4. Compute the expected PPM count values for Group 0 and Group 1 as described above.
5. Write the expected PPM count values into registers 0x60-0x63 as described above, setting bit 7 of both
registers 0x61 and 0x63.
6. Set the value 0xff into register 0x64 for an approximate PPM count tolerance of 1100-1400 PPM.
7. Reset the retimer CDR by setting and then clearing bits 3:2 of register 0x0a.
2.) If I need to change more registers than 1.) , could you share it?
3.) If DS110DF410 is not suitable for 11.0957Gbps, could you introduce other retimer products?
【Connections】
Optical signal ⇒ SFP ⇒ CDR ⇒ LSI
【Issues】
If optical cable is under 60km, CDR locked. However more than 60km, CDR doesn't lock.
Channel Registers 0x02 shows below
Locked case:0xDC
Unlocked case:repeat the value 0x04 and 0x00
【Current CDR register settings】
Related CDR register setting is as follow.
Other registers are default setting.
■Rate Setting
Channel Register
0x2F: 0xD4
0x60: 0x7B
0x61: 0xB7
0x62: 0x7B
0x63: 0xB7
0x64: 0xFF
■CTLE and DFE Adpt Mode
Channel Register
0x31: 0x60
■Other settings
Channel Register
0x1E: 0xE1
Best Regards,
ttd