
Chapter 14: Arria V GZ Transceiver Native PHY IP Core 14–13
Standard PCS Parameters
November 2012 Altera Corporation Altera Transceiver PHY IP Core
User Guide
Phase Compensation FIFO
The phase compensation FIFO assures clean data transfer to and from the FPGA
fabric by compensating for the clock phase difference between the low-speed parallel
clock and FPGA fabric interface clock. Table 14–13 describes the options for the phase
compensation FIFO.
Byte Ordering Block Parameters
The RX byte ordering block realigns the data coming from the byte deserializer. This
block is necessary when the PCS to FPGA fabric interface width is greater than the
PCS datapath. Because the timing of the RX PCS reset logic is indeterminate, the byte
ordering at the output of the byte deserializer may or may not match the original byte
ordering of the transmitted data. Table 14–14 describes the byte ordering block
parameters.
Table 14–13. Phase Compensation FIFO Parameters
Parameter Range Description
TX FIFO mode
low_latency
register_fifo
The following 2 modes are possible:
■ low_latency: This mode adds 3–4 cycles of latency to the TX
datapath.
■ register_fifo: In this mode the FIFO is replaced by registers to
reduce the latency through the PCS. Use this mode for
protocols that require deterministic latency, such as CPRI.
RX FIFO mode
low_latency
register_fifo
The following 2 modes are possible:
■ low_latency: This mode adds 2–3 cycles of latency to the TX
datapath.
■ register_fifo: In this mode the FIFO is replaced by registers to
reduce the latency through the PCS. Use this mode for
protocols that require deterministic latency, such as CPRI.
Enable tx_std_pcfifo_full port On/Off
When you turn this option On, the TX Phase compensation FIFO
outputs a FIFO full status flag.
Enable tx_std_pcfifo_empty port On/Off
When you turn this option On, the TX Phase compensation FIFO
outputs a FIFO empty status flag.
Enable rx_std_pcfifo_full port On/Off
When you turn this option On, the RX Phase compensation FIFO
outputs a FIFO full status flag.
Enable rx_std_pcfifo_empty port On/Off
When you turn this option On, the RX Phase compensation FIFO
outputs a FIFO empty status flag.
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