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Added testmode to transmitter

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-pin driven testmode driven..b/c fpga designers often don't like software
-and because it's really convenient, press a push button and see a pattern appear
-removed protocol description, goes in README.md, there should only be one source for documentation
-shortened signal names for ecfg
-changed to "clk" input now that everything is single clock
This commit is contained in:
Andreas Olofsson 2015-05-01 17:47:24 -04:00
parent 93f0fb6220
commit 20534a6ed1
1 changed files with 55 additions and 107 deletions
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162
elink/hdl/etx_protocol.v
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@ -1,112 +1,50 @@
//########################################################################
//# ELINK TX Protocol block
//########################################################################
//#
//# The etx_protocol block implements a transmitter for communicating with
//# the Epiphany receiver per the documentation seen below.
//#
//# The output transaction has an option of the bursting where data of
//# the new transaction is sent without the address. In such a case the
//# address of the transaction will be determined in the receiver according
//# to the address of the previous transaction.
//#
//# ___ ___ ___ ___ ___ ___
//# lclk _| |___| |___| |___| |___| |___| |_
//#
//# -------------------------------
//# frame ______/
//# --- --- --- --- ---
//# data XXXXXXX 0 X 1 X 2 X 3 X 4 X .....
//# --- --- --- --- ---
//#
//# Transaction structure:
//# -------------------------
//# byte0 -> 00000000
//# byte1 -> ctrlmode[3:0],dstaddr[31:28]
//# byte2 -> dstaddr[27:20]
//# byte3 -> dstaddr[19:12]
//# byte4 -> dstaddr[11:4]
//# byte5 -> dstaddr[3:0],datamode[1:0],write,access
//# byte6 -> data[31:24] (or srcaddr[31:24] if read transaction)
//# byte7 -> data[23:16] (or srcaddr[23:16] if read transaction)
//# byte8 -> data[15:8] (or srcaddr[15:8] if read transaction)
//# *byte9 -> data[7:0] (or srcaddr[7:0] if read transaction)
//# byte10 -> data[63:56]
//# byte11 -> data[55:48]
//# byte12 -> data[47:40]
//# byte13 -> data[39:32]
//# **byte14 -> data[31:24]
//# ...
//# ...
//# ...
//#
//# * byte9 is the last byte of 32 bit write or read transaction
//#
//# ** if 64 bit write transaction, data of byte14 is the first data byte of
//# bursting transaction
//#
//# -- The data is transmitted MSB first but in 32bits resolution. If we want
//# to transmit 64 bits it will be [31:0] (msb first) and then [63:32]
//# (msb first)
//#
//# Wait indication to the transmitter (from Epiphany chip receiver):
//#
//# When one of the secondary fifos becomes full we send wait indication
//# to the transmitter.
//# There is some uncertainty regarding how long it will take for the wait
//# control to stop the transmitter (we have synchronization on the way,
//# which may cause +/-1 cycle of uncertainty).
//# Our main fifo on the input port of the receiver is robust enough
//# (has enough entries) to receive all of the transactions sent during the
//# time of "wait traveling" without loosing any information.
//# But the uncertainty mentioned above forces us to start from empty fifo
//# every time after wait indication is raised in order to ensure that
//# the number of available entries won't be reduced.
//#
//#####################################################################
module etx_protocol (/*AUTOARG*/
// Outputs
etx_rd_wait, etx_wr_wait, etx_wait, etx_io_wait, tx_frame_par,
tx_data_par,
// Inputs
etx_access, etx_packet, ecfg_tx_tp_enable, ecfg_dataout,
ecfg_tx_enable, ecfg_tx_gpio_enable, ecfg_access, ecfg_packet,
reset, tx_lclk_div4, tx_rd_wait, tx_wr_wait
reset, clk, testmode, etx_access, etx_packet, tx_enable, tp_enable,
gpio_enable, gpio_data, chipid, tx_rd_wait, tx_wr_wait
);
parameter PW = 104;
parameter AW = 32;
parameter DW = 32;
parameter ID = 12'h000;
//Bus side
//Clock/reset
input reset;
input clk;
//Puts transmit in testmode
input testmode;
//System side
input etx_access;
input [PW-1:0] etx_packet;
//Pushback signals
output etx_rd_wait;
output etx_wr_wait;
output etx_wait; //for pipeline
output etx_io_wait; //for arbiter
//Enables transmit test pattern
input ecfg_tx_tp_enable;
input [8:0] ecfg_dataout;
input ecfg_tx_enable;
input ecfg_tx_gpio_enable;
//Test Insertion
input ecfg_access;
input [PW-1:0] ecfg_packet;
//Enble transmit
input tx_enable; //transmit enable
input tp_enable; //testmode enable
input gpio_enable;//gpio enable
input [8:0] gpio_data; //gpio mode data
input [11:0] chipid; //chip id
// IO side (8 eLink bytes at a time)
input reset;
input tx_lclk_div4;// Parallel-rate clock from eClock block
//Interface to IO
output [7:0] tx_frame_par;
output [63:0] tx_data_par;
input tx_rd_wait; // The wait signals are passed through
input tx_wr_wait; // to the emesh interfaces
//############
//###################################################################
//# Local regs & wires
//############
//###################################################################
reg etx_sample; //hold for second cycle
reg [7:0] tx_frame_par;
reg [127:0] tx_data_reg; //sample transaction on one clock cycle
@ -119,22 +57,33 @@ module etx_protocol (/*AUTOARG*/
wire [AW-1:0] etx_dstaddr;
wire [DW-1:0] etx_data;
wire [AW-1:0] etx_srcaddr;
wire access_mux;
wire ecfg_access_sync;
wire [PW-1:0] packet_mux;
//Synchronize access signal
synchronizer #(.DW(1)) synchronizer(.out (ecfg_access_sync),
.in (ecfg_access),
.clk (tx_lclk_div4),
.reset (reset)
);
wire [PW-1:0] etx_packet_mux;
reg [PW-1:0] testpacket;
//Testmode logic
always @( posedge clk or posedge reset )
if(reset)
testpacket[PW-1:0] <= 'd0;
else if(testmode)
if(~testpacket[1])//initiate write
testpacket[PW-1:0]<={32'h55555555,//src
32'h55555555,//data
chipid[11:0],20'b0,//dst
4'b0,2'b10,2'b11};//32bit write
else //initiate read
testpacket[PW-1:0]<={ID,12'hF03,`ERX_RR,2'b0,//src
32'haaaaaaaa,//dummy data
chipid[11:0],20'b0,//read from address
4'b0,2'b10,2'b01};//32bit read
assign access_mux = ecfg_access_sync | etx_access;
assign packet_mux[PW-1:0] = ecfg_access_sync ? ecfg_packet[PW-1:0] :
etx_packet[PW-1:0];
assign etx_packet_mux[PW-1:0] = testmode ? testpacket[PW-1:0] :
etx_packet[PW-1:0];
//Access always on in test mode (assumes no other traffic)
assign etx_access_mux = testmode | etx_access;
//Transmit packet enable
assign etx_enable = testmode | tx_enable;
//packet to emesh bundle
packet2emesh p2m (
@ -147,12 +96,11 @@ module etx_protocol (/*AUTOARG*/
.data_out (etx_data[31:0]),
.srcaddr_out (etx_srcaddr[31:0]),
// Inputs
.packet_in (packet_mux[PW-1:0]));
.packet_in (etx_packet_mux[PW-1:0])
);
// TODO: Bursts
always @( posedge tx_lclk_div4 or posedge reset )
always @( posedge clk or posedge reset )
begin
if(reset)
begin
@ -162,7 +110,7 @@ module etx_protocol (/*AUTOARG*/
end
else
begin
if( access_mux & etx_sample ) //first cycle
if( etx_enable & etx_access & etx_sample ) //first cycle
begin
etx_sample <= 1'b0;
tx_frame_par[7:0] <= 8'h3F;
@ -176,7 +124,7 @@ module etx_protocol (/*AUTOARG*/
etx_dstaddr[3:0], etx_datamode[1:0], etx_write, etx_access // B5
};
end
else if(~etx_sample ) //second cycle (1)
else if(etx_enable & ~etx_sample ) //second cycle (1)
begin
etx_sample <= 1'b1;
tx_frame_par[7:0] <= 8'hFF;
@ -203,7 +151,7 @@ module etx_protocol (/*AUTOARG*/
.out (etx_rd_wait),
// Inputs
.in (tx_rd_wait),
.clk (tx_lclk_div4),
.clk (clk),
.reset (reset)
);
@ -211,7 +159,7 @@ module etx_protocol (/*AUTOARG*/
.out (etx_wr_wait),
// Inputs
.in (tx_wr_wait),
.clk (tx_lclk_div4),
.clk (clk),
.reset (reset)
);