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OpenFPGA/openfpga_flow/benchmarks/iwls2005/pci/rtl/pci_target32_sm.v

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//////////////////////////////////////////////////////////////////////
//// ////
//// File name: pci_target32_sm.v ////
//// ////
//// This file is part of the "PCI bridge" project ////
//// http://www.opencores.org/cores/pci/ ////
//// ////
//// Author(s): ////
//// - Tadej Markovic, tadej@opencores.org ////
//// ////
//// All additional information is avaliable in the README.txt ////
//// file. ////
//// ////
//// ////
//////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2000 Tadej Markovic, tadej@opencores.org ////
//// ////
//// This source file may be used and distributed without ////
//// restriction provided that this copyright statement is not ////
//// removed from the file and that any derivative work contains ////
//// the original copyright notice and the associated disclaimer. ////
//// ////
//// This source file is free software; you can redistribute it ////
//// and/or modify it under the terms of the GNU Lesser General ////
//// Public License as published by the Free Software Foundation; ////
//// either version 2.1 of the License, or (at your option) any ////
//// later version. ////
//// ////
//// This source is distributed in the hope that it will be ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
//// PURPOSE. See the GNU Lesser General Public License for more ////
//// details. ////
//// ////
//// You should have received a copy of the GNU Lesser General ////
//// Public License along with this source; if not, download it ////
//// from http://www.opencores.org/lgpl.shtml ////
//// ////
//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: pci_target32_sm.v,v $
// Revision 1.11 2003/12/19 11:11:30 mihad
// Compact PCI Hot Swap support added.
// New testcases added.
// Specification updated.
// Test application changed to support WB B3 cycles.
//
// Revision 1.10 2003/08/08 16:36:33 tadejm
// Added 'three_left_out' to pci_pciw_fifo signaling three locations before full. Added comparison between current registered cbe and next unregistered cbe to signal wb_master whether it is allowed to performe burst or not. Due to this, I needed 'three_left_out' so that writing to pci_pciw_fifo can be registered, otherwise timing problems would occure.
//
// Revision 1.9 2003/01/27 16:49:31 mihad
// Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
//
// Revision 1.8 2003/01/21 16:06:56 mihad
// Bug fixes, testcases added.
//
// Revision 1.7 2002/09/24 19:09:17 mihad
// Number of state bits define was removed
//
// Revision 1.6 2002/09/24 18:30:00 mihad
// Changed state machine encoding to true one-hot
//
// Revision 1.5 2002/08/22 09:07:06 mihad
// Fixed a bug and provided testcase for it. Target was responding to configuration cycle type 1 transactions.
//
// Revision 1.4 2002/02/19 16:32:37 mihad
// Modified testbench and fixed some bugs
//
// Revision 1.3 2002/02/01 15:25:12 mihad
// Repaired a few bugs, updated specification, added test bench files and design document
//
// Revision 1.2 2001/10/05 08:14:30 mihad
// Updated all files with inclusion of timescale file for simulation purposes.
//
// Revision 1.1.1.1 2001/10/02 15:33:47 mihad
// New project directory structure
//
//
`include "pci_constants.v"
// synopsys translate_off
`include "timescale.v"
// synopsys translate_on
module pci_target32_sm
(
// system inputs
clk_in,
reset_in,
// master inputs
pci_frame_in,
pci_irdy_in,
pci_idsel_in,
pci_frame_reg_in,
pci_irdy_reg_in,
pci_idsel_reg_in,
// target response outputs
pci_trdy_out,
pci_stop_out,
pci_devsel_out,
pci_trdy_en_out,
pci_stop_en_out,
pci_devsel_en_out,
ad_load_out,
ad_load_on_transfer_out,
// address, data, bus command, byte enable in/outs
pci_ad_reg_in,
pci_ad_out,
pci_ad_en_out,
pci_cbe_reg_in,
pci_cbe_in,
bckp_trdy_en_in,
bckp_devsel_in,
bckp_trdy_in,
bckp_stop_in,
pci_trdy_reg_in,
pci_stop_reg_in,
// backend side of state machine with control signals to pci_io_mux ...
address_out,
addr_claim_in,
bc_out,
bc0_out,
data_out,
data_in,
be_out,
next_be_out,
req_out,
rdy_out,
addr_phase_out,
bckp_devsel_out,
bckp_trdy_out,
bckp_stop_out,
last_reg_out,
frame_reg_out,
fetch_pcir_fifo_out,
load_medium_reg_out,
sel_fifo_mreg_out,
sel_conf_fifo_out,
load_to_pciw_fifo_out,
load_to_conf_out,
same_read_in,
norm_access_to_config_in,
read_completed_in,
read_processing_in,
target_abort_in,
disconect_wo_data_in,
disconect_w_data_in,
target_abort_set_out,
pciw_fifo_full_in,
pcir_fifo_data_err_in,
wbw_fifo_empty_in,
wbu_del_read_comp_pending_in,
wbu_frame_en_in
) ;
/*----------------------------------------------------------------------------------------------------------------------
Various parameters needed for state machine and other stuff
----------------------------------------------------------------------------------------------------------------------*/
parameter S_IDLE = 3'b001 ;
parameter S_WAIT = 3'b010 ;
parameter S_TRANSFERE = 3'b100 ;
/*==================================================================================================================
System inputs.
==================================================================================================================*/
// PCI side clock and reset
input clk_in,
reset_in ;
/*==================================================================================================================
PCI interface signals - bidirectional signals are divided to inputs and outputs in I/O cells instantiation
module. Enables are separate signals.
==================================================================================================================*/
// master inputs
input pci_frame_in,
pci_irdy_in,
pci_idsel_in ;
input pci_frame_reg_in,
pci_irdy_reg_in,
pci_idsel_reg_in ;
// target response outputs
output pci_trdy_out,
pci_stop_out,
pci_devsel_out ;
output pci_trdy_en_out,
pci_stop_en_out,
pci_devsel_en_out ;
output ad_load_out ;
output ad_load_on_transfer_out ;
// address, data, bus command, byte enable in/outs
input [31:0] pci_ad_reg_in ;
output [31:0] pci_ad_out ;
output pci_ad_en_out ;
input [3:0] pci_cbe_reg_in ;
input [3:0] pci_cbe_in ;
input bckp_trdy_en_in ;
input bckp_devsel_in ;
input bckp_trdy_in ;
input bckp_stop_in ;
input pci_trdy_reg_in ;
input pci_stop_reg_in ;
/*==================================================================================================================
Other side of PCI Target state machine
==================================================================================================================*/
// Data, byte enables, bus commands and address ports
output [31:0] address_out ; // current request address output - registered
input addr_claim_in ; // current request address claim input
output [3:0] bc_out ; // current request bus command output - registered
output bc0_out ; // current cycle RW signal output
input [31:0] data_in ; // for read operations - current dataphase data input
output [31:0] data_out ; // for write operations - current request data output - registered
output [3:0] be_out ; // current dataphase byte enable outputs - registered
output [3:0] next_be_out ; // next dataphase byte enable outputs - NOT registered
// Port connection control signals from PCI FSM
output req_out ; // Read is requested to WB master
output rdy_out ; // DATA / ADDRESS selection when read or write - registered
output addr_phase_out ; // Indicates address phase and also fast-back-to-back address phase - registered
output bckp_devsel_out ; // DEVSEL output (which is registered) equivalent
output bckp_trdy_out ; // TRDY output (which is registered) equivalent
output bckp_stop_out ; // STOP output (which is registered) equivalent
output last_reg_out ; // Indicates last data phase - registered
output frame_reg_out ; // FRAME output signal - registered
output fetch_pcir_fifo_out ;// Read enable for PCIR_FIFO when when read is finishen on WB side
output load_medium_reg_out ;// Load data from PCIR_FIFO to medium register (first data must be prepared on time)
output sel_fifo_mreg_out ; // Read data selection between PCIR_FIFO and medium register
output sel_conf_fifo_out ; // Read data selection between Configuration registers and "FIFO"
output load_to_pciw_fifo_out ;// Write enable to PCIW_FIFO
output load_to_conf_out ; // Write enable to Configuration space registers
/*==================================================================================================================
Status
==================================================================================================================*/
input same_read_in ; // Indicates the same read request (important when read is finished on WB side)
input norm_access_to_config_in ; // Indicates the access to Configuration space with MEMORY commands
input read_completed_in ; // Indicates that read request is completed on WB side
input read_processing_in ; // Indicates that read request is processing on WB side
input target_abort_in ; // Indicates target abort termination
input disconect_wo_data_in ; // Indicates disconnect without data termination
input disconect_w_data_in ; // Indicates disconnect with data termination
input pciw_fifo_full_in ; // Indicates that write PCIW_FIFO is full
input pcir_fifo_data_err_in ; // Indicates data error on current data read from PCIR_FIFO
input wbw_fifo_empty_in ; // Indicates that WB SLAVE UNIT has no data to be written to PCI bus
input wbu_del_read_comp_pending_in ; // Indicates that WB S<>AVE UNIT has a delayed read pending
input wbu_frame_en_in ; // Indicates that WB SLAVE UNIT is accessing the PCI bus (important if
// address on PCI bus is also claimed by decoder in this PCI TARGET UNIT
output target_abort_set_out ; // Signal used to be set in configuration space registers
/*==================================================================================================================
END of input / output PORT DEFINITONS !!!
==================================================================================================================*/
// Delayed frame signal for determining the address phase
reg previous_frame ;
// Delayed read completed signal for preparing the data from pcir fifo
reg read_completed_reg ;
// Delayed disconnect with/without data for stop loading data to PCIW_FIFO
//reg disconect_wo_data_reg ;
wire config_disconnect ;
wire disconect_wo_data = disconect_wo_data_in || config_disconnect ;
wire disconect_w_data = disconect_w_data_in ;
// Delayed frame signal for determining the address phase!
always@(posedge clk_in or posedge reset_in)
begin
if (reset_in)
begin
previous_frame <= #`FF_DELAY 1'b0 ;
read_completed_reg <= #`FF_DELAY 1'b0 ;
end
else
begin
previous_frame <= #`FF_DELAY pci_frame_reg_in ;
read_completed_reg <= #`FF_DELAY read_completed_in ;
end
end
// Address phase is when previous frame was 1 and this frame is 0 and frame isn't generated from pci master (in WBU)
wire addr_phase = (previous_frame && ~pci_frame_reg_in && ~wbu_frame_en_in) ;
`ifdef HOST
`ifdef NO_CNF_IMAGE
// Wire tells when there is configuration (read or write) command with IDSEL signal active
wire config_access = 1'b0 ;
// Write and read progresses are used for determining next state
wire write_progress = ( (read_completed_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ||
(~read_processing_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ) ;
wire read_progress = ( (read_completed_in && wbw_fifo_empty_in) ) ;
`else
// Wire tells when there is configuration (read or write) command with IDSEL signal active
wire config_access = (pci_idsel_reg_in && pci_cbe_reg_in[3]) && (~pci_cbe_reg_in[2] && pci_cbe_reg_in[1]) && // idsel asserted with correct bus command(101x)
(pci_ad_reg_in[1:0] == 2'b00) ; // has to be type 0 configuration cycle
// Write and read progresses are used for determining next state
wire write_progress = ( (norm_access_to_config_in) ||
(read_completed_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ||
(~read_processing_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ) ;
wire read_progress = ( (~read_completed_in && norm_access_to_config_in) ||
(read_completed_in && wbw_fifo_empty_in) ) ;
`endif
`else
// Wire tells when there is configuration (read or write) command with IDSEL signal active
wire config_access = (pci_idsel_reg_in && pci_cbe_reg_in[3]) && (~pci_cbe_reg_in[2] && pci_cbe_reg_in[1]) && // idsel asserted with correct bus command(101x)
(pci_ad_reg_in[1:0] == 2'b00) ; // has to be type 0 configuration cycle
// Write and read progresses are used for determining next state
wire write_progress = ( (norm_access_to_config_in) ||
(read_completed_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ||
(~read_processing_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ) ;
wire read_progress = ( (~read_completed_in && norm_access_to_config_in) ||
(read_completed_in && wbw_fifo_empty_in) ) ;
`endif
// Signal for loading data to medium register from pcir fifo when read completed from WB side!
wire prepare_rd_fifo_data = (read_completed_in && ~read_completed_reg) ;
// Write allowed to PCIW_FIFO
wire write_to_fifo = ((read_completed_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in) ||
(~read_processing_in && ~pciw_fifo_full_in && ~wbu_del_read_comp_pending_in)) ;
// Read allowed from PCIR_FIFO
wire read_from_fifo = (read_completed_in && wbw_fifo_empty_in) ;
`ifdef HOST
`ifdef NO_CNF_IMAGE
// Read request is allowed to be proceed regarding the WB side
wire read_request = (~read_completed_in && ~read_processing_in) ;
`else
// Read request is allowed to be proceed regarding the WB side
wire read_request = (~read_completed_in && ~read_processing_in && ~norm_access_to_config_in) ;
`endif
`else
// Read request is allowed to be proceed regarding the WB side
wire read_request = (~read_completed_in && ~read_processing_in && ~norm_access_to_config_in) ;
`endif
// Critically calculated signals are latched in this clock period (address phase) to be used in the next clock period
reg rw_cbe0 ;
reg wr_progress ;
reg rd_progress ;
reg rd_from_fifo ;
reg rd_request ;
reg wr_to_fifo ;
reg same_read_reg ;
always@(posedge clk_in or posedge reset_in)
begin
if (reset_in)
begin
rw_cbe0 <= #`FF_DELAY 1'b0 ;
wr_progress <= #`FF_DELAY 1'b0 ;
rd_progress <= #`FF_DELAY 1'b0 ;
rd_from_fifo <= #`FF_DELAY 1'b0 ;
rd_request <= #`FF_DELAY 1'b0 ;
wr_to_fifo <= #`FF_DELAY 1'b0 ;
same_read_reg <= #`FF_DELAY 1'b0 ;
end
else
begin
if (addr_phase)
begin
rw_cbe0 <= #`FF_DELAY pci_cbe_reg_in[0] ;
wr_progress <= #`FF_DELAY write_progress ;
rd_progress <= #`FF_DELAY read_progress ;
rd_from_fifo <= #`FF_DELAY read_from_fifo ;
rd_request <= #`FF_DELAY read_request ;
wr_to_fifo <= #`FF_DELAY write_to_fifo ;
same_read_reg <= #`FF_DELAY same_read_in ;
end
end
end
`ifdef HOST
`ifdef NO_CNF_IMAGE
wire norm_access_to_conf_reg = 1'b0 ;
wire cnf_progress = 1'b0 ;
`else
reg norm_access_to_conf_reg ;
reg cnf_progress ;
always@(posedge clk_in or posedge reset_in)
begin
if (reset_in)
begin
norm_access_to_conf_reg <= #`FF_DELAY 1'b0 ;
cnf_progress <= #`FF_DELAY 1'b0 ;
end
else
begin
if (addr_phase)
begin
norm_access_to_conf_reg <= #`FF_DELAY norm_access_to_config_in ;
cnf_progress <= #`FF_DELAY config_access ;
end
end
end
`endif
`else
reg norm_access_to_conf_reg ;
reg cnf_progress ;
always@(posedge clk_in or posedge reset_in)
begin
if (reset_in)
begin
norm_access_to_conf_reg <= #`FF_DELAY 1'b0 ;
cnf_progress <= #`FF_DELAY 1'b0 ;
end
else
begin
if (addr_phase)
begin
norm_access_to_conf_reg <= #`FF_DELAY norm_access_to_config_in ;
cnf_progress <= #`FF_DELAY config_access ;
end
end
end
`endif
// Signal used in S_WAIT state to determin next state
wire s_wait_progress = (
(~cnf_progress && rw_cbe0 && wr_progress && ~target_abort_in) ||
(~cnf_progress && ~rw_cbe0 && same_read_reg && rd_progress && ~target_abort_in && ~pcir_fifo_data_err_in) ||
(~cnf_progress && ~rw_cbe0 && ~same_read_reg && norm_access_to_conf_reg && ~target_abort_in) ||
(cnf_progress && ~target_abort_in)
) ;
// Signal used in S_TRANSFERE state to determin next state
wire s_tran_progress = (
(rw_cbe0 && !disconect_wo_data) ||
(~rw_cbe0 && !disconect_wo_data && !target_abort_in && !pcir_fifo_data_err_in)
) ;
// Clock enable for PCI state machine driven directly from critical inputs - FRAME and IRDY
wire pcit_sm_clk_en ;
// FSM states signals indicating the current state
reg state_idle ;
reg state_wait ;
reg sm_transfere ;
reg backoff ;
reg state_default ;
wire state_backoff = sm_transfere && backoff ;
wire state_transfere = sm_transfere && !backoff ;
always@(posedge clk_in or posedge reset_in)
begin
if ( reset_in )
backoff <= #`FF_DELAY 1'b0 ;
else if ( state_idle )
backoff <= #`FF_DELAY 1'b0 ;
else
backoff <= #`FF_DELAY (state_wait && !s_wait_progress) ||
(sm_transfere && !s_tran_progress && !pci_frame_in && !pci_irdy_in) ||
backoff ;
end
assign config_disconnect = sm_transfere && (norm_access_to_conf_reg || cnf_progress) ;
// Clock enable module used for preserving the architecture because of minimum delay for critical inputs
pci_target32_clk_en pci_target_clock_en
(
.addr_phase (addr_phase),
.config_access (config_access),
.addr_claim_in (addr_claim_in),
.pci_frame_in (pci_frame_in),
.state_wait (state_wait),
.state_transfere (sm_transfere),
.state_default (state_default),
.clk_enable (pcit_sm_clk_en)
);
reg [2:0] c_state ; //current state register
reg [2:0] n_state ; //next state input to current state register
// state machine register control
always@(posedge clk_in or posedge reset_in)
begin
if (reset_in) // reset state machine to S_IDLE state
c_state <= #`FF_DELAY S_IDLE ;
else
if (pcit_sm_clk_en) // if conditions are true, then FSM goes to next state!
c_state <= #`FF_DELAY n_state ;
end
// state machine logic
always@(c_state)
begin
case (c_state)
S_IDLE :
begin
state_idle <= 1'b1 ;
state_wait <= 1'b0 ;
sm_transfere <= 1'b0 ;
state_default <= 1'b0 ;
n_state <= S_WAIT ;
end
S_WAIT :
begin
state_idle <= 1'b0 ;
state_wait <= 1'b1 ;
sm_transfere <= 1'b0 ;
state_default <= 1'b0 ;
n_state <= S_TRANSFERE ;
end
S_TRANSFERE :
begin
state_idle <= 1'b0 ;
state_wait <= 1'b0 ;
sm_transfere <= 1'b1 ;
state_default <= 1'b0 ;
n_state <= S_IDLE ;
end
default :
begin
state_idle <= 1'b0 ;
state_wait <= 1'b0 ;
sm_transfere <= 1'b0 ;
state_default <= 1'b1 ;
n_state <= S_IDLE ;
end
endcase
end
// if not retry and not target abort
// NO CRITICAL SIGNALS
wire trdy_w = (
(state_wait && ~cnf_progress && rw_cbe0 && wr_progress && ~target_abort_in) ||
(state_wait && ~cnf_progress && ~rw_cbe0 && same_read_reg && rd_progress && ~target_abort_in && !pcir_fifo_data_err_in) ||
(state_wait && ~cnf_progress && ~rw_cbe0 && ~same_read_reg && norm_access_to_conf_reg && ~target_abort_in) ||
(state_wait && cnf_progress && ~target_abort_in)
) ;
// if not disconnect without data and not target abort (only during reads)
// MUST BE ANDED WITH CRITICAL ~FRAME
wire trdy_w_frm = (
(state_transfere && !cnf_progress && !norm_access_to_conf_reg && rw_cbe0 && !disconect_wo_data) ||
(state_transfere && !cnf_progress && !norm_access_to_conf_reg && ~rw_cbe0 && !disconect_wo_data && ~pcir_fifo_data_err_in) ||
(state_transfere && !cnf_progress && !norm_access_to_conf_reg && disconect_w_data && pci_irdy_reg_in &&
((~rw_cbe0 && ~pcir_fifo_data_err_in) || rw_cbe0))
) ;
// if not disconnect without data and not target abort (only during reads)
// MUST BE ANDED WITH CRITICAL ~FRAME AND IRDY
wire trdy_w_frm_irdy = ( ~bckp_trdy_in ) ;
// TRDY critical module used for preserving the architecture because of minimum delay for critical inputs
pci_target32_trdy_crit pci_target_trdy_critical
(
.trdy_w (trdy_w),
.trdy_w_frm (trdy_w_frm),
.trdy_w_frm_irdy (trdy_w_frm_irdy),
.pci_frame_in (pci_frame_in),
.pci_irdy_in (pci_irdy_in),
.pci_trdy_out (pci_trdy_out)
);
// if target abort or retry
// NO CRITICAL SIGNALS
wire stop_w = (
(state_wait && target_abort_in) ||
(state_wait && ~cnf_progress && rw_cbe0 && ~wr_progress) ||
(state_wait && ~cnf_progress && ~rw_cbe0 && same_read_reg && ~rd_progress) ||
(state_wait && ~cnf_progress && ~rw_cbe0 && same_read_reg && rd_progress && pcir_fifo_data_err_in) ||
(state_wait && ~cnf_progress && ~rw_cbe0 && ~same_read_reg && ~norm_access_to_conf_reg)
) ;
// if asserted, wait for deactivating the frame
// MUST BE ANDED WITH CRITICAL ~FRAME
wire stop_w_frm = (
(state_backoff && ~bckp_stop_in)
) ;
// if target abort or if disconnect without data (after data transfere)
// MUST BE ANDED WITH CRITICAL ~FRAME AND ~IRDY
wire stop_w_frm_irdy = (
(state_transfere && (disconect_wo_data)) ||
(state_transfere && ~rw_cbe0 && pcir_fifo_data_err_in)
) ;
// STOP critical module used for preserving the architecture because of minimum delay for critical inputs
pci_target32_stop_crit pci_target_stop_critical
(
.stop_w (stop_w),
.stop_w_frm (stop_w_frm),
.stop_w_frm_irdy (stop_w_frm_irdy),
.pci_frame_in (pci_frame_in),
.pci_irdy_in (pci_irdy_in),
.pci_stop_out (pci_stop_out)
);
// if OK to respond and not target abort
// NO CRITICAL SIGNALS
wire devs_w = (
(addr_phase && config_access) ||
(addr_phase && ~config_access && addr_claim_in) ||
(state_wait && ~target_abort_in && !(~cnf_progress && ~rw_cbe0 && same_read_reg && rd_progress && pcir_fifo_data_err_in) )
) ;
// if not target abort (only during reads) or if asserted, wait for deactivating the frame
// MUST BE ANDED WITH CRITICAL ~FRAME
wire devs_w_frm = (
(state_transfere && rw_cbe0) ||
(state_transfere && ~rw_cbe0 && ~pcir_fifo_data_err_in) ||
(state_backoff && ~bckp_devsel_in)
) ;
// if not target abort (only during reads)
// MUST BE ANDED WITH CRITICAL ~FRAME AND IRDY
wire devs_w_frm_irdy = (
(state_transfere && ~rw_cbe0 && pcir_fifo_data_err_in)
) ;
// DEVSEL critical module used for preserving the architecture because of minimum delay for critical inputs
pci_target32_devs_crit pci_target_devsel_critical
(
.devs_w (devs_w),
.devs_w_frm (devs_w_frm),
.devs_w_frm_irdy (devs_w_frm_irdy),
.pci_frame_in (pci_frame_in),
.pci_irdy_in (pci_irdy_in),
.pci_devsel_out (pci_devsel_out)
);
// signal used in AD enable module with preserving the hierarchy because of minimum delay for critical inputs
assign pci_ad_en_out = (
(addr_phase && config_access && ~pci_cbe_reg_in[0]) ||
(addr_phase && ~config_access && addr_claim_in && ~pci_cbe_reg_in[0]) ||
(state_wait && ~rw_cbe0) ||
(state_transfere && ~rw_cbe0) ||
(state_backoff && ~rw_cbe0 && ~pci_frame_reg_in)
) ;
wire fast_back_to_back = (addr_phase && ~pci_irdy_reg_in) ;
// if cycle will progress or will not be stopped
// NO CRITICAL SIGNALS
wire ctrl_en =
/*(~wbu_frame_en_in && fast_back_to_back) ||*/
(addr_phase && config_access) ||
(addr_phase && ~config_access && addr_claim_in) ||
(state_wait) ||
(state_transfere && ~(pci_frame_reg_in && ~pci_irdy_reg_in && (~pci_stop_reg_in || ~pci_trdy_reg_in))) ||
(state_backoff && ~(pci_frame_reg_in && ~pci_irdy_reg_in && (~pci_stop_reg_in || ~pci_trdy_reg_in))) ;
assign pci_trdy_en_out = ctrl_en ;
assign pci_stop_en_out = ctrl_en ;
assign pci_devsel_en_out = ctrl_en ;
// target ready output signal delayed for one clock used in conjunction with irdy_reg to select which
// data are registered in io mux module - from fifo or medoum register
reg bckp_trdy_reg ;
// delayed indicators for states transfere and backoff
reg state_transfere_reg ;
reg state_backoff_reg ;
always@(posedge clk_in or posedge reset_in)
begin
if (reset_in)
begin
bckp_trdy_reg <= #`FF_DELAY 1'b1 ;
state_transfere_reg <= #`FF_DELAY 1'b0 ;
state_backoff_reg <= #`FF_DELAY 1'b0 ;
end
else
begin
bckp_trdy_reg <= #`FF_DELAY bckp_trdy_in ;
state_transfere_reg <= #`FF_DELAY state_transfere ;
state_backoff_reg <= #`FF_DELAY state_backoff ;
end
end
// Read control signals assignments
assign
fetch_pcir_fifo_out = (
(prepare_rd_fifo_data) ||
(state_wait && ~cnf_progress && ~rw_cbe0 && same_read_reg && rd_from_fifo && ~target_abort_in) ||
(bckp_trdy_en_in && ~pci_trdy_reg_in && ~cnf_progress && ~rw_cbe0 && same_read_reg && rd_from_fifo && ~pci_irdy_reg_in)
) ;
assign ad_load_out = (state_wait) ;
assign ad_load_on_transfer_out = (bckp_trdy_en_in && ~rw_cbe0) ;
assign load_medium_reg_out = (
(prepare_rd_fifo_data) ||
(state_wait && ~rw_cbe0 && ~cnf_progress && same_read_reg && rd_from_fifo && ~target_abort_in) ||
(~pci_irdy_reg_in && ~rw_cbe0 && ~cnf_progress && same_read_reg && rd_from_fifo && ~pci_trdy_reg_in && bckp_trdy_en_in)
) ;
assign sel_fifo_mreg_out = (~pci_irdy_reg_in && ~bckp_trdy_reg) ;
`ifdef HOST
`ifdef NO_CNF_IMAGE
assign sel_conf_fifo_out = 1'b0 ;
`else
assign sel_conf_fifo_out = (cnf_progress || norm_access_to_conf_reg) ;
`endif
`else
assign sel_conf_fifo_out = (cnf_progress || norm_access_to_conf_reg) ;
`endif
// Write control signals assignments
assign
load_to_pciw_fifo_out = (
(state_wait && (~cnf_progress && ~norm_access_to_conf_reg) && rw_cbe0 && wr_to_fifo && ~target_abort_in) ||
(state_transfere_reg && ~state_backoff && rw_cbe0 && wr_to_fifo /*&& ~disconect_wo_data_reg*/ && ~pci_irdy_reg_in && ~bckp_trdy_reg && (~cnf_progress && ~norm_access_to_conf_reg)) ||
((state_backoff || state_backoff_reg) && rw_cbe0 && wr_to_fifo && ~pci_irdy_reg_in && ~bckp_trdy_reg && (~cnf_progress && ~norm_access_to_conf_reg))
) ;
`ifdef HOST
`ifdef NO_CNF_IMAGE
assign load_to_conf_out = 1'b0 ;
`else
assign load_to_conf_out = (
(state_transfere_reg && cnf_progress && rw_cbe0 && ~pci_irdy_reg_in && ~bckp_trdy_reg) ||
(state_transfere_reg && norm_access_to_conf_reg && rw_cbe0 && ~pci_irdy_reg_in && ~bckp_trdy_reg)
) ;
`endif
`else
assign load_to_conf_out = (
(state_transfere_reg && cnf_progress && rw_cbe0 && ~pci_irdy_reg_in && ~bckp_trdy_reg) ||
(state_transfere_reg && norm_access_to_conf_reg && rw_cbe0 && ~pci_irdy_reg_in && ~bckp_trdy_reg)
) ;
`endif
// General control sigal assignments
assign addr_phase_out = addr_phase ;
assign last_reg_out = (pci_frame_reg_in && ~pci_irdy_reg_in) ;
assign frame_reg_out = pci_frame_reg_in ;
assign bckp_devsel_out = bckp_devsel_in ;
assign bckp_trdy_out = bckp_trdy_in ;
assign bckp_stop_out = bckp_stop_in ;
assign target_abort_set_out = (bckp_devsel_in && bckp_trdy_in && ~bckp_stop_in && bckp_trdy_en_in) ;
// request signal for delayed sinc. module
reg master_will_request_read ;
always@(posedge clk_in or posedge reset_in)
begin
if ( reset_in )
master_will_request_read <= #`FF_DELAY 1'b0 ;
else
master_will_request_read <= #`FF_DELAY ((state_wait && ~target_abort_in) || (state_backoff && ~target_abort_set_out)) && ~cnf_progress && ~norm_access_to_conf_reg && ~rw_cbe0 && rd_request ;
end
// MORE OPTIMIZED READS, but not easy to control in a testbench!
//assign req_out = master_will_request_read ;
assign req_out = master_will_request_read && !pci_irdy_reg_in && !read_processing_in ;
// ready tells when address or data are written into fifo - RDY ? DATA : ADDRESS
assign rdy_out = ~bckp_trdy_reg ;
// data and address outputs assignments!
assign pci_ad_out = data_in ;
assign data_out = pci_ad_reg_in ;
assign be_out = pci_cbe_reg_in ;
assign next_be_out = pci_cbe_in ;
assign address_out = pci_ad_reg_in ;
assign bc_out = pci_cbe_reg_in ;
assign bc0_out = rw_cbe0 ;
endmodule
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