3. Serial RapidIO Electrical Interface > Programmable Transmit and Receive Equalization
77
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
Even numbered ports in 4x mode are associated with lanes A-D. When an even numbered port is in 1x
mode, it is associated with lane A. Odd numbered ports are always associated with lane B.
3.6.2.3
Tx and Rx Swapping
The operations in the SMACx_DLOOP_CLK_SEL register are associated with lanes. When lanes are
swapped, the channels associated with these operations must change. The user can independently swap
only the Tx or Rx lanes.
Operations on channels, as supported by the MAC Channel Configuration registers always operate on
the specific channels regardless of the lane swap settings for a MAC (see
Configuration Channel 0” on page 363
). If lane swap functionality is enabled in the system, the proper
channels must also be configured. The channel number of a transmit lane and a receive lane differs
when Tx lanes are swapped and Rx lanes are not, or vice versa.
3.7
Programmable Transmit and Receive Equalization
The Tsi578 has programmable drive strengths and de-emphasis of a transmit lane. The Tsi578 also has
the ability to internally boost the received signal. This functionality is described in the following
sections.
3.7.1
Transmit Drive Level and Equalization
The Tsi578 has programmable drive strengths and de-emphasis of a transmit lane. This ability adjusts
for the electrical characteristics that can degrade the signal quality of a link which connects a device to
the Tsi578. Decreasing the drive strength of signals also provides the ability to reduce the power
consumption of a port.
The drive strength current of each lane can be controlled through the TX_LVL field in the
x SerDes Configuration Global” on page 372
, and the TX_BOOST field in the
Configuration Channel 0” on page 363
The de-emphasis functionality can be programmed by the TX_BOOST field in the
SerDes Configuration Channel 0” on page 363
. The TX_BOOST field controls the drive level of
subsequent non-transitional bits with respect to the transitional ones. The amount of de-emphasis is
specified as a ratio of the de-emphasis drive strength to the TX_LVL drive strength, in steps of
~0.37dB.
Ti
p
The
RapidIO Interconnect Specification (Revision 1.3)
uses Lane 0, 1, 2, 3 terminology
instead of the IDT terminology of Lane A, B, C, D.
The Nominal Drive Level is 1.0 V +/-10%. Refer to the
Tsi578
Hardware Manual
for the
more information.