IP-CPRI Altera, IP-CPRI Datasheet - Page 64

• Manufacturer Part Number: IP-CPRI
• Description: IP CORE - Common Public Radio Interface (CPRI)
• Manufacturer: Altera

Specifications of IP-CPRI

• Software Application: IP CORE, Interface And Protocols, HIGH SPEED
• Supported Families: Arria II GX, Cyclone IV GX, HardCopy IV, Stratix IV
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

4–40
Figure 4–19. Single-Hop CPRI Configuration Delay Measurement Reference Points
Figure 4–20. Multi-Hop CPRI Configuration Delay Measurement Reference Points
CPRI MegaCore Function User Guide
cpri_tx_sync_rfp
REC Master
cpri_rx_rfp
SAPs
Rx Path Delay
T_T4
T_R1
T_txv_TX
T_txv_RX
Transceiver
and SFP
REC Master
cpri_tx_sync_rfp
R4
R1
Figure 4–19
function delay measurements for single-hop CPRI configurations.
CPRI requirement R-21 addresses the accuracy of the round-trip cable delay, which is
the sum of the T12 and T34 delays. The T12 and T34 delays are assumed to have the
same duration.
Figure 4–20
function delay measurements for multi-hop CPRI configurations. The duration of
TBdelay depends on your routing layer implementation.
The following sections describe the delay through the CPRI MegaCore function on the
Rx path and on the Tx path to the two SAPs—the AUX interface and the MAP
interface—and the deterministic values for transceiver latency and delay through the
IP core. They describe the calculation of the round-trip cable delay T14, the Toffset
delay, and the round-trip (SAP to SAP) delay in the single-hop and multi-hop cases.
The Rx path delay is the cumulative delay from the arrival of the first bit of a 10 ms
radio frame on the CPRI Rx interface to the start of transmission of the radio frame
data on the AUX or AxC interface.
Rx Path Delay Components
The CPRI specification defines requirements on the path to an SAP. The CPRI
MegaCore function has two relevant SAPs: the AUX interface and the MAP interface.
This section provides the information to calculate the Rx path delay to output on the
cpri_rx_rfp
T14
optical link
optical link
T34
T12
SAPs
T_R1
T_T4
R2
R3
Transceiver
T_txv_RX
and SFP
T_txv_TX
shows the reference points you can use to determine the CPRI MegaCore
shows the reference points you can use to determine the CPRI MegaCore
T_txv_TX
T_txv_RX
Transceiver
and SFP
T_R1
T_T4
Toffset
AUX IF
R4
R1
cpri_rx_rfp
cpri_tx_rfp
RE Slave
T14
rx_round_trip_delay
Routing Layer
TBdelay DL
TBdelay UL
optical link
T12
T34
RE Master
cpri_rx_rfp
R2
R3
AUX IF
Transceiver
T_txv_TX
T_txv_RX
and SFP
T_T4
T_R1
T_txv_TX
T_txv_RX
Transceiver
and SFP
T_R1
T_T4
Toffset
R4
R1
SAPs
T14
optical link
optical link
T34
T12
cpri_rx_rfp
cpri_tx_rfp
December 2010 Altera Corporation
Chapter 4: Functional Description
RE Slave
R2
R3
Transceiver
T_txv_TX
T_txv_RX
and SFP
Delay Measurement
T_R1
T_T4
Toffset
SAPs
cpri_tx_rfp
cpri_rx_rfp
RE Slave