SerialLite II IP Core User Guide

ID 683179
Date 7/13/2021
Public
Document Table of Contents

2.8.14.5. ALTGX Support Signals

The ALTGX support signals are only present on variants that use the Arria II GX and Stratix IV integrated PHY.

The ALTGX support signals are connected directly to the ALTGX instance. In many cases these signals must be shared with ALTGX instances that are implemented in the same device.

Table 14.  ALTGX Support Signals
Signal Direction Description
cal_blk_clk Input The cal_blk_clk input signal is connected to the ALTGX calibration block clock (cal_blk_clk) input. All instances of ALTGX in the same device must have their cal_blk_clk inputs connected to the same signal because there is only one calibration block per device. This input should be connected to a clock operating as recommended by the Arria II GX Device Handbook or the Stratix IV Device Handbook.
reconfig_clk Input The reconfig_clk input signal is the ALTGX dynamic reconfiguration clock. This signal must be connected as described in the Arria II GX Device Handbook or the Stratix IV Device Handbook if the ALTGX dynamic reconfiguration block is used. Otherwise, this signal must be set to 1'b0.
reconfig_togxb Input The reconfig_togxb [N:0] input signal is driven from an external dynamic reconfiguration block. The signal supports the selection of multiple transceiver channels for dynamic reconfiguration. This signal must be connected as described in the Arria II GX Device Handbook or the Stratix IV Device Handbook if the external dynamic reconfiguration block is used. Otherwise, you must set this signal to 4'b0010 for Arria II GX and Stratix IV devices.

N value is 3 for Arria II GX and Stratix IV devices.

reconfig_fromgxb Output The reconfig_fromgxb output signal is driven to an external dynamic reconfiguration block. The width of this bus depends on the number of lanes (it may require multiple transceiver QUAD blocks), and the device family (for Arria II GX and Stratix IV, the bus is wider due to offset cancellation support).

This signal identifies the transceiver channel whose settings are being transmitted to the dynamic reconfiguration. This signal must be connected as described in the Arria II GX Device Handbook or the Stratix IV Device Handbook if the external dynamic reconfiguration block is used. Otherwise, leave this signal unconnected.

For Arria II GX and Stratix IV devices, you must use the dynamic reconfiguration block because they require offset cancellation.

gxb_powerdown Input gxb_powerdown resets and powers down all circuits in the transceiver block. This signal does not affect the refclk buffers and reference clock lines.

All the gxb_powerdown input signals of cores placed in the same quad should be tied together. The gxb_powerdown signal should be tied low or should remain asserted for at least 2 ms whenever it is asserted.