I want to design a router circuit based on LS1046ARDB-PB, but without CPLD.
To do this, I need to completely understand the function of CPLD in the LS1046ARDB-PB.
Regarding the CPLD function related to SFP+, I have some question as below.
1. Due to the I2C address confliction, I2C Lines are disconnected from STF connector.
Below is the Errata regarding this issue.
"E-00002 When SFP+ module is inserted, its I2C address conflicts with that of SPD Cut SFP cage’s I2C traces Rev. B Rev. B"
=> Does this mean that SFP+ in LS1046ARDB-PB can works without I2C control of connector side SFT+ module?
2. In the CPLD circuit of LS1046ARDB-PB, STF+ related signals below are connected to CPLD.
Input : XFI1_TX_FAULT,XFI1_RX_VALID,XFI1_MOD_DEF from the STF connector.
XFI1_RETIMER_LOS from the retimer.
Output: XFI1_TX_DISABLE to the STF connector.
But, in the CPLD source cord, I cannot find any function or relation among these signals.
What does CPLD do with above signals?
Solved! Go to Solution.
1) You wrote:
> Does this mean that SFP+ in LS1046ARDB-PB can works without I2C control of connector side SFT+ module?
Your understanding is correct.
2) Levels of the XFI1_TX_FAULT, XFI1_RX_VALID, XFI1_MOD_DEF and XFI1_RETIMER_LOS can be read through the REG_SFP_STATUS of the CPLD.
Level of the XFI1_TX_DISABLE is controlled through the REG_SFP_TXEN register of the CPLD.
Thanks
1) You wrote:
> Does this mean that SFP+ in LS1046ARDB-PB can works without I2C control of connector side SFT+ module?
Your understanding is correct.
2) Levels of the XFI1_TX_FAULT, XFI1_RX_VALID, XFI1_MOD_DEF and XFI1_RETIMER_LOS can be read through the REG_SFP_STATUS of the CPLD.
Level of the XFI1_TX_DISABLE is controlled through the REG_SFP_TXEN register of the CPLD.
I understand that XFI1_TX_FAULT, XFI1_RX_VALID, XFI1_MOD_DEF and XFI1_RETIMER_LOS can be read, and XFI1_TX_DISABLE can be set as I want through CPLD.
My question is
To design SFP+ HW circuit without CPLD, what logic circuit should be implemented to make SFP+ work.
1. Should XFI1_TX_FAULT, XFI1_RX_VALID, XFI1_MOD_DEF and XFI1_RETIMER_LOS be readable ?
If yes, what action or logic should be implemented depening on read value of them
2. Should XFI1_TX_DISABLE be controled by the function of (XFI1_TX_FAULT, XFI1_RX_VALID, XFI1_MOD_DEF and XFI1_RETIMER_LOS)?
I think both question above can be answerd with same answer
1) The signals could be read as testpoints.
2) No.