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hiroshi |
/* *****************************************************************************
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* title: uart_16550_rll module *
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* description: RS232 Protocol 16550D uart (mostly supported) *
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* languages: systemVerilog *
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* *
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* Copyright (C) 2010 miyagi.hiroshi *
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* *
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* This library is free software; you can redistribute it and/or *
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* modify it under the terms of the GNU Lesser General Public *
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* License as published by the Free Software Foundation; either *
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* version 2.1 of the License, or (at your option) any later version. *
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* *
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* This library is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
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* Lesser General Public License for more details. *
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* *
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* You should have received a copy of the GNU Lesser General Public *
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* License along with this library; if not, write to the Free Software *
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111*1307 USA *
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* *
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* *** GNU LESSER GENERAL PUBLIC LICENSE *** *
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* from http://www.gnu.org/licenses/lgpl.txt *
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*****************************************************************************
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* redleaflogic,ltd *
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* miyagi.hiroshi@redleaflogic.biz *
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* $Id: uart_register.sv 108 2010-03-30 02:56:26Z hiroshi $ *
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***************************************************************************** */
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`ifdef SYN
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/* empty */
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`else
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timeunit 1ps ;
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timeprecision 1ps ;
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`endif
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import uart_package:: * ;
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module uart_register
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(
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input wire clk_i,
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input wire nrst_i,
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wb_bus wb_bus,
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uart_bus uart_bus,
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output u_reg_t u_reg,
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fifo_bus fifo_pop_trans,
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fifo_bus fifo_push_rec,
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input wire timeout_signal,
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input wire overrun,
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input wire rec_buf_empty,
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input wire trans_buf_empty
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) ;
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localparam WRITE = 1'b1 ;
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localparam READ = 1'b0 ;
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localparam ENABLE = 1'b1 ;
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localparam DISABLE = 1'b0 ;
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fifo_bus
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fifo_pop_rec(.clk_i(clk_i)),
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fifo_push_trans(.clk_i(clk_i)) ;
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logic [31:0] rdat ;
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wire [31:0] dat_i = wb_bus.dat_i ;
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wire we_i = wb_bus.we_i ;
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`ifdef ALIGN_4B
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wire uart_stb = wb_bus.cyc_i == 1'b1 && wb_bus.stb_i == 1'b1 && wb_bus.sel_i == 4'b1111 ;
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wire stb_rxd_fifo = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_RXD && u_reg.line_control_reg.divisor_access == 1'b0 ;
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wire stb_txd_fifo = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_TXD && u_reg.line_control_reg.divisor_access == 1'b0 ;
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wire stb_interrupt_enable_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_INTERRUPT_ENABLE ;
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wire stb_interrupt_ident_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_INTERRUPT_IDENT ;
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wire stb_fifo_control_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_FIFO_CONTROL ;
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wire stb_line_control_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_LINE_CONTROL ;
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wire stb_modem_control_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_MODEM_CONTROL ;
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wire stb_line_status_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_LINE_STATUS ;
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wire stb_modem_status_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_MODEM_STATUS ;
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wire stb_scratch_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_SCRATCH ;
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wire stb_baud_reg = uart_stb == 1'b1 && wb_bus.adr_i[4:2] == UART_BAUD && u_reg.line_control_reg.divisor_access == 1'b1 ;
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`else
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wire uart_stb = wb_bus.cyc_i == 1'b1 && wb_bus.stb_i == 1'b1 ;
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wire stb_rxd_fifo = wb_bus.sel_i[0] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_RXD && u_reg.line_control_reg.divisor_access == 1'b0 ;
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wire stb_txd_fifo = wb_bus.sel_i[0] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_TXD && u_reg.line_control_reg.divisor_access == 1'b0 ;
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wire stb_interrupt_enable_reg = wb_bus.sel_i[1] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_INTERRUPT_ENABLE ;
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wire stb_interrupt_ident_reg = wb_bus.sel_i[2] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_INTERRUPT_IDENT ;
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wire stb_fifo_control_reg = wb_bus.sel_i[2] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_FIFO_CONTROL ;
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wire stb_line_control_reg = wb_bus.sel_i[3] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_LINE_CONTROL ;
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wire stb_modem_control_reg = wb_bus.sel_i[0] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_MODEM_CONTROL ;
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wire stb_line_status_reg = wb_bus.sel_i[1] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_LINE_STATUS ;
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wire stb_modem_status_reg = wb_bus.sel_i[2] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_MODEM_STATUS ;
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wire stb_scratch_reg = wb_bus.sel_i[3] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_SCRATCH ;
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wire stb_baud_reg = wb_bus.sel_i[0] == 1'b1 && uart_stb == 1'b1 && wb_bus.adr_i[2:0] == UART_BAUD && u_reg.line_control_reg.divisor_access == 1'b1 ;
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`endif
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// -- assign wb_bus.intr_o = u_reg.interrupt_identification.intr_active == 1'b1 ;
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assign wb_bus.intr_o = u_reg.interrupt_pending_reg.modem_status ||
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u_reg.interrupt_pending_reg.transmitter_holding_register_empty ||
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u_reg.interrupt_pending_reg.timeout_indication ||
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u_reg.interrupt_pending_reg.receiver_data_available ||
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u_reg.interrupt_pending_reg.receiver_line_status ;
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assign wb_bus.dat_o = rdat ;
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assign wb_bus.ack_o = uart_stb == 1'b1 ; // no wait
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assign dat_i = wb_bus.dat_i ;
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// -- uart line :: read for manual -> 4.6 Modem Control Register (MCR) --
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assign uart_bus.dtr_o = u_reg.modem_control_reg.dtr == 1'b0 ;
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assign uart_bus.rts_o = u_reg.modem_control_reg.rts == 1'b0 ;
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wire cts = u_reg.modem_control_reg.loopback == 1'b1 ? uart_bus.rts_o : uart_bus.cts_i == 1'b0 ;
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wire dsr = u_reg.modem_control_reg.loopback == 1'b1 ? uart_bus.dtr_o : uart_bus.dsr_i == 1'b0 ;
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wire ri = u_reg.modem_control_reg.loopback == 1'b1 ? u_reg.modem_control_reg.out1 : uart_bus.ri_i == 1'b0 ;
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wire dcd = u_reg.modem_control_reg.loopback == 1'b1 ? u_reg.modem_control_reg.out2 : uart_bus.dcd_i == 1'b0 ;
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`ifdef ALIGN_4B
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// -- data read selector --
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always_comb begin
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unique case ({
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stb_baud_reg,
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stb_scratch_reg,
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stb_rxd_fifo,
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stb_interrupt_enable_reg,
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stb_interrupt_ident_reg,
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stb_line_control_reg,
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stb_modem_control_reg,
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stb_line_status_reg,
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stb_modem_status_reg
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})
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9'h100 : rdat = {24'h0, u_reg.baud_reg} ;
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9'h080 : rdat = {24'h0, u_reg.scratch_reg} ;
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9'h040 : rdat = {24'h0, fifo_pop_rec.pop_dat[7:0]} ;
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9'h020 : rdat = {24'h0, u_reg.interrupt_enable_reg} ;
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9'h010 : rdat = {24'h0, u_reg.interrupt_ident_reg} ;
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9'h008 : rdat = {24'h0, u_reg.line_control_reg} ;
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9'h004 : rdat = {24'h0, u_reg.modem_control_reg} ;
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9'h002 : rdat = {24'h0, u_reg.line_status_reg} ;
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9'h001 : rdat = {24'h0, u_reg.modem_status_reg} ;
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default : rdat = 32'h0 ;
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endcase
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end
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`else // ALINE_1B
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assign rdat[7:0] = stb_rxd_fifo == 1'b1 ? fifo_pop_rec.pop_dat[7:0] : 8'h0 |
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stb_baud_reg == 1'b1 ? u_reg.baud_reg : 8'h0 ;
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assign rdat[15:8] = stb_interrupt_enable_reg == 1'b1 ? u_reg.interrupt_enable_reg : 8'h0 |
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stb_line_status_reg == 1'b1 ? u_reg.line_status_reg : 8'h0 ;
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assign rdat[23:16] = stb_interrupt_ident_reg ? u_reg.interrupt_ident_reg : 8'h0 |
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stb_modem_status_reg == 1'b1 ? u_reg.modem_status_reg : 8'h0 ;
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assign rdat[31:24] = stb_line_control_reg == 1'b1 ? u_reg.line_control_reg : 8'h0 |
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stb_scratch_reg == 1'b1 ? u_reg.scratch_reg : 8'h0 ;
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`endif
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// -- fifo signal --
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wire fifo_rec_reset = u_reg.fifo_control_reg.receiver_fifo_reset == 1'b1 ;
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wire fifo_trans_reset = u_reg.fifo_control_reg.transmitter_fifo_reset == 1'b1 ;
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wire all_error_rec ;
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// -- recevied fifo --
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uart_fifo #(.DATA_WIDTH(11), .ADDR_WIDTH(4)) fifo_rec
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(
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.clk_i(clk_i),
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.nrst_i(nrst_i),
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.clear(fifo_rec_reset),
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.almost_empty_level(u_reg.fifo_control_reg.define_fifo_trigger_level),
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.fifo_pop(fifo_pop_rec.pop_slave_mp),
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.fifo_push(fifo_push_rec.push_slave_mp),
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.all_error(all_error_rec)
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) ;
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// -- transmitter fifo --
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uart_fifo #(.DATA_WIDTH(11), .ADDR_WIDTH(4)) fifo_trans
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(
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.clk_i(clk_i),
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.nrst_i(nrst_i),
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.clear(fifo_trans_reset),
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.almost_empty_level(u_reg.fifo_control_reg.define_fifo_trigger_level),
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.fifo_pop(fifo_pop_trans.pop_slave_mp),
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.fifo_push(fifo_push_trans.push_slave_mp),
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.all_error() /* N.C. */
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) ;
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// -------------------
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// -- UART REGISTER --
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// -------------------
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assign fifo_push_trans.push = stb_txd_fifo == 1'b1 && we_i == WRITE ;
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assign fifo_push_trans.push_dat = dat_i[7:0] ;
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assign fifo_pop_rec.pop = stb_rxd_fifo == 1'b1 && we_i == READ ;
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// -- interrupt enable register --
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always_ff @(posedge clk_i, negedge nrst_i) begin
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if(nrst_i == 1'b0)
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u_reg.interrupt_enable_reg <= 'h0 ;
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else if(stb_interrupt_enable_reg == 1'b1 && we_i == WRITE)
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u_reg.interrupt_enable_reg <= dat_i[7:0] ;
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else
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u_reg.interrupt_enable_reg <= u_reg.interrupt_enable_reg[7:0] ;
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end
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// -- fifo control register write only --
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always_ff @(posedge clk_i, negedge nrst_i) begin
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if(nrst_i == 1'b0)
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u_reg.fifo_control_reg <= 'hc0 ;
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else if(stb_fifo_control_reg == 1'b1 && we_i == WRITE)
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u_reg.fifo_control_reg <= dat_i[7:0] ;
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else begin
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u_reg.fifo_control_reg[7:3] <= u_reg.fifo_control_reg[7:3] ;
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u_reg.fifo_control_reg[2:1] <= 2'b00 ; // -- fifo_cleaer
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u_reg.fifo_control_reg[0] <= u_reg.fifo_control_reg[0] ;
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end
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end
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// -- line control register --
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always_ff @(posedge clk_i, negedge nrst_i) begin
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if(nrst_i == 1'b0)
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u_reg.line_control_reg <= 'h03 ;
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else if(stb_line_control_reg == 1'b1 && we_i == WRITE)
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u_reg.line_control_reg <= dat_i[7:0] ;
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else
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u_reg.line_control_reg <= u_reg.line_control_reg[7:0] ;
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end
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// -- modem control register --
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always_ff @(posedge clk_i, negedge nrst_i) begin
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if(nrst_i == 1'b0)
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u_reg.modem_control_reg <= 'h0 ;
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else if(stb_modem_control_reg == 1'b1 && we_i == WRITE)
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u_reg.modem_control_reg <= dat_i[7:0] ;
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else
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u_reg.modem_control_reg <= u_reg.modem_control_reg[7:0] ;
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end
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// -- scratch register --
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always_ff @(posedge clk_i, negedge nrst_i) begin
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if(nrst_i == 1'b0)
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u_reg.scratch_reg <= 'h0 ;
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else if(stb_scratch_reg == 1'b1 && we_i == WRITE)
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u_reg.scratch_reg <= dat_i[7:0] ;
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else
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u_reg.scratch_reg <= u_reg.scratch_reg[7:0] ;
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end
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// -- scratch register --
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always_ff @(posedge clk_i, negedge nrst_i) begin
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if(nrst_i == 1'b0)
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u_reg.baud_reg <= 'h0 ;
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else if(stb_baud_reg == 1'b1 && we_i == WRITE)
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u_reg.baud_reg <= dat_i[7:0] ;
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else
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u_reg.baud_reg <= u_reg.baud_reg[7:0] ;
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end
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// -- read for manual - 4.7 Line Status Register (LSR)
|
| 252 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 253 |
|
|
if(nrst_i == 1'b0) begin
|
| 254 |
|
|
{u_reg.line_status_reg.data_ready,
|
| 255 |
|
|
u_reg.line_status_reg.trans_fifo_empty,
|
| 256 |
|
|
u_reg.line_status_reg.trans_empty} <= #1 3'h0 ;
|
| 257 |
|
|
end
|
| 258 |
|
|
else begin
|
| 259 |
|
|
u_reg.line_status_reg.data_ready <= #1 fifo_pop_rec.empty == 1'b0 ;
|
| 260 |
|
|
u_reg.line_status_reg.trans_fifo_empty <= #1 fifo_push_trans.empty ;
|
| 261 |
|
|
u_reg.line_status_reg.trans_empty <= #1 fifo_push_trans.empty | trans_buf_empty ;
|
| 262 |
|
|
end
|
| 263 |
|
|
end // always_ff @ (posedge clk_i, negedge nrst_i)
|
| 264 |
|
|
|
| 265 |
|
|
// -- overrun error --
|
| 266 |
|
|
logic overrun_err_r ;
|
| 267 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 268 |
|
|
if(nrst_i == 1'b0)
|
| 269 |
|
|
overrun_err_r <= #1 1'b1 ;
|
| 270 |
|
|
else
|
| 271 |
|
|
overrun_err_r <= #1 overrun ;
|
| 272 |
|
|
end
|
| 273 |
|
|
wire overrun_err_set = overrun & ~overrun_err_r ;
|
| 274 |
|
|
wire overrun_err_clr = we_i == READ && stb_line_status_reg == 1'b1 ;
|
| 275 |
|
|
|
| 276 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 277 |
|
|
if(nrst_i == 1'b0)
|
| 278 |
|
|
u_reg.line_status_reg.overrun_err <= #1 1'b0 ;
|
| 279 |
|
|
else if(overrun_err_set == 1'b1)
|
| 280 |
|
|
u_reg.line_status_reg.overrun_err <= #1 1'b1 ;
|
| 281 |
|
|
else if(overrun_err_clr == 1'b1)
|
| 282 |
|
|
u_reg.line_status_reg.overrun_err <= #1 1'b0 ;
|
| 283 |
|
|
else
|
| 284 |
|
|
u_reg.line_status_reg.overrun_err <= #1 u_reg.line_status_reg.overrun_err ;
|
| 285 |
|
|
end
|
| 286 |
|
|
|
| 287 |
|
|
// -- parity error --
|
| 288 |
|
|
logic parity_err_r ;
|
| 289 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 290 |
|
|
if(nrst_i == 1'b0)
|
| 291 |
|
|
parity_err_r <= #1 1'b1 ;
|
| 292 |
|
|
else
|
| 293 |
|
|
parity_err_r <= #1 fifo_pop_rec.pop_dat[10] ;
|
| 294 |
|
|
end
|
| 295 |
|
|
wire parity_err_set = fifo_pop_rec.pop_dat[10] & ~parity_err_r ;
|
| 296 |
|
|
wire parity_err_clr = we_i == READ && stb_line_status_reg == 1'b1 ;
|
| 297 |
|
|
|
| 298 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 299 |
|
|
if(nrst_i == 1'b0)
|
| 300 |
|
|
u_reg.line_status_reg.parity_err <= #1 1'b0 ;
|
| 301 |
|
|
else if(parity_err_set == 1'b1)
|
| 302 |
|
|
u_reg.line_status_reg.parity_err <= #1 1'b1 ;
|
| 303 |
|
|
else if(parity_err_clr == 1'b1)
|
| 304 |
|
|
u_reg.line_status_reg.parity_err <= #1 1'b0 ;
|
| 305 |
|
|
else
|
| 306 |
|
|
u_reg.line_status_reg.parity_err <= #1 u_reg.line_status_reg.parity_err ;
|
| 307 |
|
|
end
|
| 308 |
|
|
|
| 309 |
|
|
// -- framing error --
|
| 310 |
|
|
logic framing_err_r ;
|
| 311 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 312 |
|
|
if(nrst_i == 1'b0)
|
| 313 |
|
|
framing_err_r <= #1 1'b1 ;
|
| 314 |
|
|
else
|
| 315 |
|
|
framing_err_r <= #1 fifo_pop_rec.pop_dat[9] ;
|
| 316 |
|
|
end
|
| 317 |
|
|
wire framing_err_set = fifo_pop_rec.pop_dat[9] & ~framing_err_r ;
|
| 318 |
|
|
wire framing_err_clr = we_i == READ && stb_line_status_reg == 1'b1 ;
|
| 319 |
|
|
|
| 320 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 321 |
|
|
if(nrst_i == 1'b0)
|
| 322 |
|
|
u_reg.line_status_reg.framing_err <= #1 1'b0 ;
|
| 323 |
|
|
else if(framing_err_set == 1'b1)
|
| 324 |
|
|
u_reg.line_status_reg.framing_err <= #1 1'b1 ;
|
| 325 |
|
|
else if(framing_err_clr == 1'b1)
|
| 326 |
|
|
u_reg.line_status_reg.framing_err <= #1 1'b0 ;
|
| 327 |
|
|
else
|
| 328 |
|
|
u_reg.line_status_reg.framing_err <= #1 u_reg.line_status_reg.framing_err ;
|
| 329 |
|
|
end
|
| 330 |
|
|
|
| 331 |
|
|
// -- break interrupt indicator --
|
| 332 |
|
|
logic break_intr_r ;
|
| 333 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 334 |
|
|
if(nrst_i == 1'b0)
|
| 335 |
|
|
break_intr_r <= #1 1'b1 ;
|
| 336 |
|
|
else
|
| 337 |
|
|
break_intr_r <= #1 fifo_pop_rec.pop_dat[8] ;
|
| 338 |
|
|
end
|
| 339 |
|
|
wire break_intr_set = fifo_pop_rec.pop_dat[8] & ~break_intr_r ;
|
| 340 |
|
|
wire break_intr_clr = we_i == READ && stb_line_status_reg == 1'b1 ;
|
| 341 |
|
|
|
| 342 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 343 |
|
|
if(nrst_i == 1'b0)
|
| 344 |
|
|
u_reg.line_status_reg.break_intr <= #1 1'b0 ;
|
| 345 |
|
|
else if(break_intr_set == 1'b1)
|
| 346 |
|
|
u_reg.line_status_reg.break_intr <= #1 1'b1 ;
|
| 347 |
|
|
else if(break_intr_clr == 1'b1)
|
| 348 |
|
|
u_reg.line_status_reg.break_intr <= #1 1'b0 ;
|
| 349 |
|
|
else
|
| 350 |
|
|
u_reg.line_status_reg.break_intr <= #1 u_reg.line_status_reg.break_intr ;
|
| 351 |
|
|
end
|
| 352 |
|
|
|
| 353 |
|
|
// -- parity error or framing error or break indication --
|
| 354 |
|
|
logic all_error_r ;
|
| 355 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 356 |
|
|
if(nrst_i == 1'b0)
|
| 357 |
|
|
all_error_r <= #1 1'b1 ;
|
| 358 |
|
|
else
|
| 359 |
|
|
all_error_r <= #1 all_error_rec | overrun ;
|
| 360 |
|
|
end
|
| 361 |
|
|
wire all_error_set = all_error_rec & ~all_error_r ;
|
| 362 |
|
|
wire all_error_clr = we_i == READ && stb_line_status_reg == 1'b1 ;
|
| 363 |
|
|
|
| 364 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 365 |
|
|
if(nrst_i == 1'b0)
|
| 366 |
|
|
u_reg.line_status_reg.all_error <= #1 1'b0 ;
|
| 367 |
|
|
else if(all_error_set == 1'b1)
|
| 368 |
|
|
u_reg.line_status_reg.all_error <= #1 1'b1 ;
|
| 369 |
|
|
else if(all_error_clr == 1'b1)
|
| 370 |
|
|
u_reg.line_status_reg.all_error <= #1 1'b0 ;
|
| 371 |
|
|
else
|
| 372 |
|
|
u_reg.line_status_reg.all_error <= #1 u_reg.line_status_reg.all_error ;
|
| 373 |
|
|
end
|
| 374 |
|
|
|
| 375 |
|
|
// -- read for manual - 4.8 Modem Status Register (MSR)
|
| 376 |
|
|
wire [3:0] modem_cont = {dcd, ri, dsr, cts} ;
|
| 377 |
|
|
logic [3:0] modem_contl ;
|
| 378 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 379 |
|
|
if(nrst_i == 1'b0)
|
| 380 |
|
|
modem_contl <= #1 4'h0 ;
|
| 381 |
|
|
else
|
| 382 |
|
|
modem_contl <= #1 modem_cont ;
|
| 383 |
|
|
end
|
| 384 |
|
|
|
| 385 |
|
|
wire [3:0] modem_pulse = modem_cont ^ modem_contl ;
|
| 386 |
|
|
|
| 387 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 388 |
|
|
if(nrst_i == 1'b0)
|
| 389 |
|
|
u_reg.modem_status_reg[3:0] <= #1 0 ;
|
| 390 |
|
|
else if(stb_modem_status_reg == 1'b1 && we_i == READ)
|
| 391 |
|
|
u_reg.modem_status_reg[3:0] <= #1 0 ;
|
| 392 |
|
|
else if(modem_pulse != 4'h0) begin
|
| 393 |
|
|
u_reg.modem_status_reg[3:0] <= #1 modem_pulse ;
|
| 394 |
|
|
end
|
| 395 |
|
|
else
|
| 396 |
|
|
u_reg.modem_status_reg[3:0] <= #1 u_reg.modem_status_reg[3:0] ;
|
| 397 |
|
|
end
|
| 398 |
|
|
|
| 399 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 400 |
|
|
if(nrst_i == 1'b0)
|
| 401 |
|
|
u_reg.modem_status_reg[7:4] <= #1 0 ;
|
| 402 |
|
|
else
|
| 403 |
|
|
u_reg.modem_status_reg[7:4] <= modem_cont ;
|
| 404 |
|
|
end
|
| 405 |
|
|
|
| 406 |
|
|
// -- read for manual - 4.3 Interrupt Identification Register (IIR) --
|
| 407 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 408 |
|
|
if(nrst_i == 1'b0) begin
|
| 409 |
|
|
u_reg.interrupt_ident_reg.interrupt_identification <= #1 NO_INTERRUPT ;
|
| 410 |
|
|
u_reg.interrupt_ident_reg.ignored_74_value_hC <= #1 4'hC ;
|
| 411 |
|
|
end
|
| 412 |
|
|
else begin
|
| 413 |
|
|
priority casex({u_reg.interrupt_pending_reg.receiver_line_status,
|
| 414 |
|
|
u_reg.interrupt_pending_reg.receiver_data_available,
|
| 415 |
|
|
u_reg.interrupt_pending_reg.timeout_indication,
|
| 416 |
|
|
u_reg.interrupt_pending_reg.transmitter_holding_register_empty,
|
| 417 |
|
|
u_reg.interrupt_pending_reg.modem_status})
|
| 418 |
|
|
5'b1xxxx : u_reg.interrupt_ident_reg.interrupt_identification <= #1 REC_LINE_STATUS ;
|
| 419 |
|
|
5'b01xxx : u_reg.interrupt_ident_reg.interrupt_identification <= #1 REC_DATA_AVAILABLE ;
|
| 420 |
|
|
5'b001xx : u_reg.interrupt_ident_reg.interrupt_identification <= #1 TIME_OUT ;
|
| 421 |
|
|
5'b0001x : u_reg.interrupt_ident_reg.interrupt_identification <= #1 TRANS_REG_EMPTY ;
|
| 422 |
|
|
5'b00001 : u_reg.interrupt_ident_reg.interrupt_identification <= #1 MODEM_STATUS ;
|
| 423 |
|
|
default : u_reg.interrupt_ident_reg <= #1 {4'hC, NO_INTERRUPT} ;
|
| 424 |
|
|
endcase // case (u_reg.interrupt_pending_reg.receiver_line_status,...
|
| 425 |
|
|
end // else: !if(nrst_i == 1'b0)
|
| 426 |
|
|
end
|
| 427 |
|
|
|
| 428 |
|
|
// -- interrupt paending register --
|
| 429 |
|
|
wire receiver_data_available_reset ;
|
| 430 |
|
|
logic [4:0] interrupt_pending_reg_set_r ;
|
| 431 |
|
|
wire [4:0] interrupt_pending_reg_reset
|
| 432 |
|
|
= {
|
| 433 |
|
|
(stb_modem_status_reg == 1'b1 && we_i == 1'b0),
|
| 434 |
|
|
((stb_txd_fifo == 1'b1 && we_i == WRITE) || (stb_interrupt_ident_reg == 1'b1 && we_i == READ)),
|
| 435 |
|
|
(stb_rxd_fifo == 1'b1 && we_i == READ),
|
| 436 |
|
|
(receiver_data_available_reset == 1'b1),
|
| 437 |
|
|
(stb_line_status_reg == 1'b1 && we_i == READ)
|
| 438 |
|
|
} ;
|
| 439 |
|
|
|
| 440 |
|
|
|
| 441 |
|
|
wire modem_status_intr = |modem_pulse[3:0] ;
|
| 442 |
|
|
wire transmitter_holding_regster_empty_intr = fifo_pop_trans.empty & trans_buf_empty ;
|
| 443 |
|
|
wire timeout_indication_intr = timeout_signal ;
|
| 444 |
|
|
wire receiver_data_available_intr = fifo_push_rec.almost_full ;
|
| 445 |
|
|
// wire receiver_line_status_intr = all_error_rec | overrun ;
|
| 446 |
|
|
wire receiver_line_status_intr ;
|
| 447 |
|
|
assign receiver_line_status_intr = u_reg.line_status_reg.break_intr |
|
| 448 |
|
|
u_reg.line_status_reg.framing_err |
|
| 449 |
|
|
u_reg.line_status_reg.parity_err |
|
| 450 |
|
|
u_reg.line_status_reg.overrun_err ;
|
| 451 |
|
|
|
| 452 |
|
|
wire [4:0] interrupt_pending_reg_set_w
|
| 453 |
|
|
= {
|
| 454 |
|
|
(modem_status_intr == 1'b1 && u_reg.interrupt_enable_reg.modem_status == 1'b1),
|
| 455 |
|
|
(transmitter_holding_regster_empty_intr == 1'b1 && u_reg.interrupt_enable_reg.trans_holding_reg_empty == 1'b1),
|
| 456 |
|
|
(timeout_indication_intr == 1'b1 && u_reg.interrupt_enable_reg.rec_data_available == 1'b1),
|
| 457 |
|
|
(receiver_data_available_intr == 1'b1 && u_reg.interrupt_enable_reg.rec_data_available == 1'b1),
|
| 458 |
|
|
(receiver_line_status_intr == 1'b1 && u_reg.interrupt_enable_reg.rec_line_status == 1'b1)
|
| 459 |
|
|
} ;
|
| 460 |
|
|
|
| 461 |
|
|
wire [4:0] interrupt_pending_reg_set = interrupt_pending_reg_set_w & ~(interrupt_pending_reg_set_r) ;
|
| 462 |
|
|
|
| 463 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 464 |
|
|
if(nrst_i == 1'b0)
|
| 465 |
|
|
interrupt_pending_reg_set_r <= #1 5'h0 ;
|
| 466 |
|
|
else
|
| 467 |
|
|
interrupt_pending_reg_set_r <= #1 interrupt_pending_reg_set_w ;
|
| 468 |
|
|
end
|
| 469 |
|
|
assign receiver_data_available_reset = interrupt_pending_reg_set_r[1] & ~interrupt_pending_reg_set_w[1] ;
|
| 470 |
|
|
|
| 471 |
|
|
always_ff @(posedge clk_i, negedge nrst_i) begin
|
| 472 |
|
|
if(nrst_i == 1'b0)
|
| 473 |
|
|
u_reg.interrupt_pending_reg <= #1 5'h00 ;
|
| 474 |
|
|
else if(interrupt_pending_reg_set != 0)
|
| 475 |
|
|
u_reg.interrupt_pending_reg <= #1 u_reg.interrupt_pending_reg | interrupt_pending_reg_set ;
|
| 476 |
|
|
else if(interrupt_pending_reg_reset != 0)
|
| 477 |
|
|
u_reg.interrupt_pending_reg <= #1 u_reg.interrupt_pending_reg & ~(interrupt_pending_reg_reset) ;
|
| 478 |
|
|
else
|
| 479 |
|
|
u_reg.interrupt_pending_reg <= #1 u_reg.interrupt_pending_reg ;
|
| 480 |
|
|
end
|
| 481 |
|
|
|
| 482 |
|
|
endmodule
|
| 483 |
|
|
|
| 484 |
|
|
/// END OF FILE ///
|
