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Altera_Forum
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15 years ago

ALTGX for A2GX always outputs K28.5- ?!

Hello, I perform an RTL simulation (ModelSim) of an ALTGX transmitter-only for an Arria II GX. The transmitter is set to take a 20-bit input. I use Basic mode, 4 lanes unbonded. After I releas...
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Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

The same problem with simulating altgx 3gb/s 1 lane 16bit+8b/10b basic mode transmitter+receiver cyclone iv gx.

The receiver works fine after correct initialization procedure, transmitter do not. I have added pause, like you, but no success, it is in stuck state.

The initializing procedure: (timescale = 1ps) 

initial begin
		gxb_powerdown <= 0;
		pll_areset <= 0;
		rx_analogreset <= 0;
		rx_digitalreset <= 0;
		tx_digitalreset <= 0;
		
	# 10000 gxb_powerdown <= 1;
		pll_areset <= 1;
		rx_analogreset <= 1;
		rx_digitalreset <= 1;
		tx_digitalreset <= 1;
		
	# 1000000	pll_areset <= 0;
		gxb_powerdown <= 0;
		wait( pll_locked) repeat( 300) @ (posedge tx_clkout);
		tx_digitalreset <= 0;
		wait( ~busy) repeat( 3) @ (posedge tx_clkout);
		rx_analogreset <= 0;
		wait( rx_freqlocked)# 4000000 rx_digitalreset <= 0;
	end

This - "wait( pll_locked) repeat( 300) @ (posedge tx_clkout)" do not help.

There is no required pause in handbook's description.