Altera Stratix GX Transceiver User Manual

Page 273

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Altera Corporation

9–47

January 2005

Stratix GX Transceiver User Guide

Reset Control & Power Down

output rxdigitalreset;//GXB Receive digital reset

output rxanalogreset;//Receive power down signal

reg rxdigitalreset;

reg rxdigitalreset_rx_cruclk;

reg rxdigitalreset_rx_coreclk_Q;

reg rxanalogreset;

//Parameter value of T (2ms)based on the fastest clock (or 3.1875

Gbps)

parameter WAITSTATE_TIMER_VALUE = 1000000;

reg [19:0]waitstate_timer; //timer - for actual value, refer

stratix data sheet

//Receive Reset Sequence

always @(posedge rx_cruclk or posedge async_reset)

if(async_reset)

begin

rxanalogreset <= 1'b1;

rxdigitalreset_rx_cruclk <= 1'b1;

waitstate_timer <=

WAITSTATE_TIMER_VALUE;

end

else

begin

if(sync_reset)

begin

rxanalogreset <= 1'b1;

rxdigitalreset_rx_cruclk<= 1'b1;

waitstate_timer <=

WAITSTATE_TIMER_VALUE;

end

else

begin

rxanalogreset <= 1'b0;

if (rx_freqlocked)

begin

if(waitstate_timer == 0)

begin

waitstate_timer

<= waitstate_timer;

if(receive_digitalreset)

rxdigitalreset_rx_cruclk <= 1'b1;

else

rxdigitalreset_rx_cruclk <= 1'b0;

end

else

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