Xilinx 7 Series User Manual

72 www.xilinx.com 7 Series FPGAs GTP Transceivers User Guide
UG482 (v1.9) December 19, 2016
Chapter 2: Shared Features
Use Mode
Reading loop values out of the digital monitor requires a clock on input clock port
DMONITORCLK, change adaptation loop select through DRP, and monitor output
DMONITOROUT. Set the DMONITOR_CFG attribute via the DRP port to the appropriate loop for
monitoring. The DRP location of DMONITOR_CFG is:
0x086[15:0] = DMONITOR_CFG[15:0]
0x087[7:0] = DMONITOR_CFG[23:16]
The output can be observed on DMONITOROUT. The signals from the digital monitor are LSB
aligned and asynchronous.
Capturing the Digital Monitor Output
The DMONITOROUT signals change slowly in comparison to the RXUSRCLK2s. One way to
capture the DMONITOROUT is described here.
reg [7:0] compare1, compare2, dmonitorout_sync;
always@ (posedge RXUSRCLK2)
begin
if (reset)
begin
compare1 <= 8'd0;
compare2 <= 8'd0;
dmonitorout_sync <= 8'd0;
end
else
begin
compare1 <= DMONITOROUT;
compare2 <= compare1;
if (compare1 == compare2)
dmonitorout_sync <= compare2;
else
dmonitorout_sync<=dmonitorout_sync;
end //else
end //always
Any method that captures the information successfully is valid.
Capturing the Digital Monitor Output Through Software
The dmonitorout_sync described in the Verilog code in the section above can be mapped into host
processor memory to capture the digital monitor output. The channel DRP port can be mapped into
host processor memory to select the adaptation loop to be monitored.
The following example C code is provided as an illustration. The drpread and drpwrite functions are
DRP operations described in Usage Model, page 69. The captureDMON function reads
dmonitorout_sync register described in the above Verilog code.
//////////////////////////////////////////
// Function Prototypes
//////////////////////////////////////////
void drpwrite(unsigned int drpaddress, unsigned int drpvalue);
usigned int drpread(unsigned int drpaddress);
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Xilinx 7 Series Specifications

General

Brand	Xilinx
Model	7 Series
Category	Computer Hardware
Language	English