Quartus® Prime Pro Edition User Guide: Platform Designer

ID 683609
Date 4/17/2025
Public
Document Table of Contents

6.12.5.3.2. CSR interface for TDEST setting

A CSR interface sets TDEST for each transmitter interface. The following are the details of the CSR interface:

  • A Single register with all TDEST values concatenated.
  • An AXI-Lite interface accesses CSR.

The CSR interface has registers through which user can configure the TDEST for each of the RX interfaces. If the value configured in the TDEST registers are invalid (that is, out-of-range compared to the Number of Transmitter Interfaces parameter setting for the IP), then the corresponding error status flag indicates this error.

For CTRL_REG_0, the values below configure the TDEST values for the RX_[0:7] interfaces. The four bit value indicates to which TX the RX interface should be connected (that is, a point-to-point connection). If the TDEST register value changes while one transfer is already ongoing, then only after that ongoing transfer is over (after TLAST), the new TDEST register value takes effect.

Table 204.   CTRL_REG_0 Configuration Values of TDEST for RX_[0:7] interfaces
Base Address Register Name Type Description
Field TDEST Register Name Reset Value
0x0000 CTRL_REG_0 R/W [3:0] RX_0_TDEST 4'b0
[7:4] RX_1_TDEST 4'b0
[11:8] RX_2_TDEST 4'b0
[15:12] RX_3_TDEST 4'b0
[19:16] RX_4_TDEST 4'b0
[23:20] RX_5_TDEST 4'b0
[27:24] RX_6_TDEST 4'b0
[31:28] RX_7_TDEST 4'b0

For CTRL_REG_1, the values below configures TDEST values for RX_[8:15] interfaces.

Table 205.   CTRL_REG_1 Configuration Values of TDEST for RX_[8:15] interfaces
Base Address Register Name Type Description
Field TDEST Register Name Reset Value
0x0004 CTRL_REG_1 R/W [3:0] RX_8_TDEST 4'b0
[7:4] RX_9_TDEST 4'b0
[11:8] RX_10_TDEST 4'b0
[15:12] RX_11_TDEST 4'b0
[19:16] RX_12_TDEST 4'b0
[23:20] RX_13_TDEST 4'b0
[27:24] RX_14_TDEST 4'b0
[31:28] RX_15_TDEST 4'b0

For example, in a 2x16 system if you want to make the following connection:

RX0 to TX15 and RX1 to TX8 

Then, CTRL_REG_0 = 32’h0000_008F.

Where F=15 in hexadecimal for TX15 at the LSB which is RX0. 8 is 8 for TX8 at the second LSB which is RX1. The rest follows accordingly.

TDEST updates are flagged at an RX port once the latest CSR TDEST loads into the crossbar.