Intel IXP2800 and IXP2850 Network Processors
Signal Description
Datasheet
33
The next group in
Table 8 is used to communicate flow control information between two network
processors.
SPI4_ZQ2
SPI4_ZQ1
I/O
Impedance Match. The ZQ1 and ZQ2
pins should be connected together
through a 100-ohm resistor. Internal
circuitry matches the impedance of
the internal termination resistors on all
LVDS input pairs to value of this
resistor.
2
Total
95
1. Floating and unused LVDS inputs should be terminated, as specified in
Section 3.3.Table 7.
MSF Data Signals (Sheet 4 of 4)
Signal Name
I/O
Type
SPI-4 Use
CSIX Use
Description
Number
Table 8.
MSF Flow Control Signals (Sheet 1 of 2)
Signal Name
I/O
Type
SPI-4 Use1
(Note 1)
CSIX Use
Description
Number
FC_TXCCLK_H,
FC_TXCCLK_L
O
LVDS
RSCLK
TXCCLK
Flow Control Egress Clock. Reference for
TXCSRB, TXCDAT, TXCSOF, TXCPAR,
and RXCFC.
FIFO status clock for SPI-4.
2
FC_TXCSRB_H,
FC_TXCSRB_L
O
LVDS
--
TXCSRB
Flow Control Egress Serialized Ready
Bits.
2
FC_TXCDAT_H(0)
FC_TXCDAT_H(1)
FC_TXCDAT_H(2)
FC_TXCDAT_H(3)
FC_TXCDAT_L(0)
FC_TXCDAT_L(1)
FC_TXCDAT_L(2)
FC_TXCDAT_L(3)
O
LVDS
RSTAT[1:0]
TXCDAT[3:0]
Flow Control Egress Data – CSIX.
Receive FIFO Status – SPI-4.
Note: When used in LVDS RSTAT mode,
only FC_TXCDAT_H/_L[1:0] are used.
FC_TXCDAT_H/_L[3:2] are unused.
8
FC_TXCSOF_H,
FC_TXCSOF_L
O
LVDS
--
TXCSOF
Flow Control Egress Start of Frame.
2
FC_TXCPAR_H,
FC_TXCPAR_L
O
LVDS
--
TXCPAR
Flow Control Egress Parity.
2
FC_TXCFC_H,
FC_TXCFC_L
I
LVDS
--
TXCFC
Flow Control Egress FIFO Full. This signal
is received relative to TXCCLK, but is
treated as asynchronous; also used
during Flow Control pin training.2
2
FC_RXCCLK_H,
FC_RXCCLK_L
I
LVDS
TSCLK
RXCCLK
Transmit Status Ingress Clock. Used to
register RXCSRB, RXCDAT, RXCSOF,
and RXCPAR.
FIFO status clock for SPI-4.
22
FC_RXCSRB_H,
FC_RXCSRB_L
I
LVDS
--
RXCSRB
Flow Control Ingress Serialized Ready
2