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Direct L1 Control and Status Interface

If you turn on Enable direct Z.130.0 alarm bits access interface in the CPRI v6.0 parameter editor, the direct L1 control and status interface is available. This interface provides direct access to the Z.130.0 alarm and reset signals (loss of frame (LOF), loss of signal (LOS), service access point (SAP) defect indication (SDI), remote alarm indication (RAI). and reset request or acknowledge) in the CPRI hyperframe.

If you connect the AUX interface of your RE slave IP core to a network switch or other routing layer rather than directly to the downstream RE master, or if you do not fully connect the AUX interface to the

downstream RE master, you can use this Z.130.0 access interface to streamline the transfer of reset requests and SDI alarms across hops.

This interface has higher transmit priority than access through the CPRI v6.0 IP core registers. This interface has the following types of signals:

• _local_ signals are output signals from the IP core about the state of this IP core, and also indicate the

IP core will assert the relevant outgoing Z.130.0 bit in the next CPRI hyperframe according to the transmit priority of this interface.

• _assert signals are input signals the application can use to request that the IP core assert the relevant

outgoing Z.130.0 bit in the next CPRI hyperframe according to the transmit priority of this interface. You can also connect these signals in an RE master to the corresponding _req output signals of the

upstream RE slave in a multi-hop configuration, to support efficient transfer of reset requests and SDI alarms to the IP core.

• _remote signals are output signals from the IP core that indicate the IP core received a Z.130.0 byte on

the CPRI link with the relevant bit asserted by the CPRI link partner.

• _req signals are also output signals from the IP core that indicate the IP core received a Z.130.0 byte on

the CPRI link with the relevant bit asserted by the CPRI link partner. However, these signals are intended to be passed downstream in a multi-hop configuration. If the IP core is an RE slave, and it connects to an RE master through the Z.130.0 alarm and reset interface in a multi-hop configuration, you can connect the RE slave IP core _req output signal directly to the corresponding _assert input

signal on the downstream RE master for efficient communication of the reset request or SDI alarm.

Table 3-10: Direct L1 Control and Status Interface Signals

All interface signals are clocked by the cpri_clkout clock.

Signal Name Direction Description

z130_local_lof Output Indicates the IP core has detected a local loss of frame. In

this case, the state_l1_synch output signal indicates the

L1 synchronization state machine is in state XACQ1 or XACQ2

z130_local_los Output Indicates the IP core has detected a local loss of signal. The

IP core asserts this flag if it detects excessive 8B/10B errors that trigger the assertion of the optional L1 debug rx_lcv

output signal or the xcvr_los output signal and the rx_ los field of the L1_CONFIG register.

UG-20008

2016.07.22 Direct L1 Control and Status Interface 3-35

Functional Description Altera Corporation

Signal Name Direction Description

z130_sdi_assert Input Indicates that the master service access point (SAP) is not

available. Possible causes for this situation are equipment error or that the connected slave IP core is forwarding an SDI request it detected to the current RE CPRI master IP core through a direct connection.

z130_local_rai Output Indicates that either the z130_local_lof or the z130_

local_los signal is high; clears when both of those two

signals are low. Logical OR of two output signals z130_ local_lof and z130_local_los.

z130_reset_assert Input Reset request from the application or from an RE slave to

the current RE CPRI master IP core through a direct connection.

z130_remote_lof Output Indicates LOF received in Z.130.0 control byte from

remote CPRI link partner.

z130_remote_los Output Indicates LOS received in Z.130.0 control byte from

remote CPRI link partner.

z130_sdi_req Output Indicates remote SAP defect indication received in Z.130.0

control byte from remote CPRI link master. If the current CPRI IP core is an RE slave in a multi-hop configuration, you should connect this output signal directly to the z130_ sdi_assert input signal of the downstream RE master.

z130_remote_rai Output Asserts when either z130_remote_lof or z130_remote_

los is asserted, and clears when both z130_remote_lof

and z130_remote_los have the value of 0.

z130_reset_req Output If the current IP core is a CPRI link slave, indicates the IP

core received a reset request in the Z.130.0 control byte from the remote CPRI link master.

If the current IP core is a CPRI link master, indicates the IP core received a reset acknowledgement in the Z.130.0 control byte from the remote CPRI link slave.

3-36 Direct L1 Control and Status Interface 2016.07.22UG-20008

Figure 3-27: sdi_assert to sdi_req on Direct L1 Control and Status Interface

cpri_clkout Master z130_sdi_assert DL Frame Z.130.0[2] (Internal)

Slave z130_sdi_req

Assert for at Least One Clock Cycle to Ensure at Least One Hyperframe Z.13.0[2] Asserted

Nearest

Z.130.0 Bit [2] Next Z.130.0 Bit [2]Is Not Asserted

For Longer Slave sdi_req Assertion (More than One Hyperframe), Hold sdl_assert for More than One Hyperframe or Assert for One Clock Cycle 3 Clock Cycles before Z.130.0 (See AUX Status Signals) at Each Hyperframe

Assertion after Detecting the

First Z.130.0[2] Assertion Hold Assertion for OneHyperframe until the Next Z.130.0[2] Detection

Figure 3-28: reset_assert to reset_req on Direct L1 Control and Status Interface

cpri_clkout Master z130_reset_assert DL Frame Z.130.0[0] (Internal)

Slave z130_reset_req

Assert for at Least One Clock Cycle to Ensure at Least One Hyperframe Z.13.0[2] Asserted

Nearest Next 10 Hyperframe Z.130.0 Bit [0] Is Asserted Automatically

After Another Nine Hyperframes

Assertion after Detecting the

Tenth Z.130.0[2] Assertion Hold Assertion for at Least One Hyperframe Slave Sends Next Five Hyperframes

of Z.130.0[0] for Acknowledgement Acknowledgement Signal Holdfor at Least One Hyperframe UL Frame Z.130.0[0] (Internal)

Master z130_reset_req UG-20008

2016.07.22 Direct L1 Control and Status Interface 3-37

Functional Description Altera Corporation

Figure 3-29: LOF, LOS, and RAI on Direct L1 Control and Status Interface

cpri_clkout z130_local/remote_lof z130_local/remote_los

z130_local/remote_rai LOF Happens after RX State Machine Lost Comma Synchronization

May or May Not Follow Up LOS

RX State Is Recovering from Comma Resynchronization

remote_lof/los/rai

Only Happens to Slave RAI Asserts wheneverLOF or LOS Asserts

Hyperframe Synchronization Achieved

Related Information

FLSAR Register on page 5-11