LCP-8500A4EDR
Preliminary
DELTA ELECTRONICS, INC.
6 2008/7/16
Rev. 0A
www.deltaww.com
Low speed electrical control pins and 2-wire interface
In addition to the 2-wire serial interface, the SFP+ module has the following low speed pins for control and
status:
‧
TX_Fault
‧
TX_Disable
‧
RS0/RS1
‧
MOD_ABS
‧
RX_LOS
1. TX_Fault
.TX_Fault is a module output pin that when High, indicates that the module transmitter has detected a fault
condition related to laser operation or safety.
The TX_Fault output pin is an open drain/collector and must be pulled p to the Host_Vcc with 4.7k-10k
ohms on the host board.
2. TX_Disable
TX_Disable is a module input pin. When TX_Disable is asserted High or Left open, the SFP+ module
transmitter output must be turned off. The TX_DIS pin must be pulled up to VccT in the SFP+ module.
3. RS0/RS1
RS0 and RS1 are module input rate select pins and are pulled low to VeeT with a > 30k
Ω
resistor in the
module. RS0 is an input hardware pin which optionally selects the optical receives data path rate
coverage for an SFP+ module. RS1 is an input hardware pin which optionally selects the optical transmits
path data rate coverage for an SFP+ module.
RS1 is commonly connected to VeeT or VeeR in the legacy SFP modules. The host needs to ensure that
it will not be damaged if this pin is connected to VeeT or VeeR in the module.
4. MOD_ABS
Mod_ABS is pulled up to Host_Vcc with 4.7k-10k ohms on the host board and connected to VeeT or VeeR
in the SFP+ module. MOD_ABS is then asserted “High” when the SFP+ module is physically absent from
a host slot. In the SFP MSA (INF8074i) this pin had the same function but is called MOD_DEF0.
5. SCL/SDA
SCL is the 2-wire interface clock and SDA is the 2-wire interface data line. SCL and SDA are pulled up to
a voltage in the range of 3.14V to 3.46V on the host.
6. RX_LOS
RX_LOS when High Indicated an optical signal level below that specified in the relevant standard. The
RX_LOS pin is an open drain/collector outpit and must be pulled up to host Vcc with a 4.7k-10k ohms on
the host board.
RX_LOS assert min and de-assert max are defined in the relevant standard. To avoid spurious transition
of RX_LOS a minimum hysteresis of 0.5 dBo is recommended.
