-------------------------------------------------------------------------------
--
-- Copyright (C) 2011
-- ASTRON (Netherlands Institute for Radio Astronomy) <http://www.astron.nl/>
-- P.O.Box 2, 7990 AA Dwingeloo, The Netherlands
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program 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 General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
--
-------------------------------------------------------------------------------
-- RO read only (no VHDL present to access HW in write mode)
-- WO write only (no VHDL present to access HW in read mode)
-- WE write event (=WO)
-- WR write control, read control
-- RW read status, write control
-- RC read, clear on read
-- FR FIFO read
-- FW FIFO write
--
-- wi Bits R/W Name Default Description |REG_DDR3|
-- =============================================================================
-- 0 [0] WE burstbegin 0x0
-- 1 [0] WO wr_not_rd 0x0
-- 2 [0] RO done 0x1
-- 3 [1..0] RO cal_result 0x1 cal_fail & cal_ok
-- 4 [0] RO waitrequest_n 0x1
-- 5 [31..0] WO address 0x0
-- 6 [31..0] WO burstsize 0x0
-- 7 [0] WR flush 0x0
-- =============================================================================
LIBRARY IEEE, common_lib, diag_lib;
USE IEEE.STD_LOGIC_1164.ALL;
USE common_lib.common_pkg.ALL;
USE common_lib.common_mem_pkg.ALL;
USE diag_lib.diag_pkg.ALL;
ENTITY io_ddr_reg IS
PORT (
-- Clocks and reset
mm_rst : IN STD_LOGIC; -- reset synchronous with mm_clk
mm_clk : IN STD_LOGIC; -- memory-mapped bus clock
dp_rst : IN STD_LOGIC; -- reset synchronous with dp_clk
dp_clk : IN STD_LOGIC; -- other clock domain clock
-- Memory Mapped Slave in mm_clk domain
sla_in : IN t_mem_mosi; -- actual ranges defined by c_mm_reg
sla_out : OUT t_mem_miso; -- actual ranges defined by c_mm_reg
-- MM registers in st_clk domain
dvr_miso : IN t_mem_ctlr_miso;
dvr_mosi : OUT t_mem_ctlr_mosi
);
END io_ddr_reg;
ARCHITECTURE rtl OF io_ddr_reg IS
CONSTANT c_mm_reg : t_c_mem := (latency => 1,
adr_w => ceil_log2(8),
dat_w => c_word_w, -- Use MM bus data width = c_word_w = 32 for all MM registers
nof_dat => 8,
init_sl => '0');
-- Registers in mm_clk domain
SIGNAL mm_dvr_miso : t_mem_ctlr_miso;
SIGNAL mm_dvr_mosi : t_mem_ctlr_mosi;
BEGIN
------------------------------------------------------------------------------
-- MM register access in the mm_clk domain
-- . Hardcode the shared MM slave register directly in RTL instead of using
-- the common_reg_r_w instance. Directly using RTL is easier when the large
-- MM register has multiple different fields and with different read and
-- write options per field in one MM register.
------------------------------------------------------------------------------
p_mm_reg : PROCESS (mm_rst, mm_clk)
BEGIN
IF mm_rst = '1' THEN
sla_out <= c_mem_miso_rst;
mm_dvr_mosi <= c_mem_ctlr_mosi_rst;
ELSIF rising_edge(mm_clk) THEN
-- Read access defaults
sla_out.rdval <= '0';
mm_dvr_mosi.burstbegin <= '0';
-- Write access: set register value
IF sla_in.wr = '1' THEN
CASE TO_UINT(sla_in.address(c_mm_reg.adr_w-1 DOWNTO 0)) IS
-- Write Block Sync
WHEN 0 =>
mm_dvr_mosi.burstbegin <= sla_in.wrdata(0);
WHEN 1 =>
mm_dvr_mosi.wr <= sla_in.wrdata(0);
mm_dvr_mosi.rd <= NOT(sla_in.wrdata(0));
WHEN 5 =>
mm_dvr_mosi.address <= sla_in.wrdata(c_mem_ctlr_address_w-1 DOWNTO 0);
WHEN 6 =>
mm_dvr_mosi.burstsize <= sla_in.wrdata(c_mem_ctlr_burstsize_w-1 DOWNTO 0);
WHEN 7 =>
mm_dvr_mosi.flush <= sla_in.wrdata(0);
WHEN OTHERS => NULL; -- unused MM addresses
END CASE;
-- Read access: get register value
ELSIF sla_in.rd = '1' THEN
sla_out <= c_mem_miso_rst; -- set unused rddata bits to '0' when read
sla_out.rdval <= '1'; -- c_mm_reg.latency = 1
CASE TO_UINT(sla_in.address(c_mm_reg.adr_w-1 DOWNTO 0)) IS
-- Read Block Sync
WHEN 2 =>
sla_out.rddata(0) <= mm_dvr_miso.done;
WHEN 3 =>
sla_out.rddata(1 DOWNTO 0) <= mm_dvr_miso.cal_fail & mm_dvr_miso.cal_ok;
WHEN 4 =>
sla_out.rddata(0) <= mm_dvr_miso.waitrequest_n;
WHEN 7 =>
sla_out.rddata(0) <= mm_dvr_mosi.flush;
WHEN OTHERS => NULL; -- unused MM addresses
END CASE;
END IF;
END IF;
END PROCESS;
------------------------------------------------------------------------------
-- Transfer register value between mm_clk and st_clk domain.
-- If the function of the register ensures that the value will not be used
-- immediately when it was set, then the transfer between the clock domains
-- can be done by wires only. Otherwise if the change in register value can
-- have an immediate effect then the bit or word value needs to be transfered
-- using:
--
-- . common_async --> for single-bit level signal
-- . common_spulse --> for single-bit pulse signal
-- . common_reg_cross_domain --> for a multi-bit (a word) signal
--
-- Typically always use a crossing component for the single bit signals (to
-- be on the safe side) and only use a crossing component for the word
-- signals if it is necessary (to avoid using more logic than necessary).
------------------------------------------------------------------------------
u_spulse_en_evt : ENTITY common_lib.common_spulse
PORT MAP (
in_rst => mm_rst,
in_clk => mm_clk,
in_pulse => mm_dvr_mosi.burstbegin,
in_busy => OPEN,
out_rst => dp_rst,
out_clk => dp_clk,
out_pulse => dvr_mosi.burstbegin
);
u_async_wr : ENTITY common_lib.common_async
GENERIC MAP (
g_rst_level => '0'
)
PORT MAP (
rst => dp_rst,
clk => dp_clk,
din => mm_dvr_mosi.wr,
dout => dvr_mosi.wr
);
u_async_rd : ENTITY common_lib.common_async
GENERIC MAP (
g_rst_level => '0'
)
PORT MAP (
rst => dp_rst,
clk => dp_clk,
din => mm_dvr_mosi.rd,
dout => dvr_mosi.rd
);
u_async_flush : ENTITY common_lib.common_async
GENERIC MAP (
g_rst_level => '0'
)
PORT MAP (
rst => dp_rst,
clk => dp_clk,
din => mm_dvr_mosi.flush,
dout => dvr_mosi.flush
);
u_async_done : ENTITY common_lib.common_async
GENERIC MAP (
g_rst_level => '0'
)
PORT MAP (
rst => mm_rst,
clk => mm_clk,
din => dvr_miso.done,
dout => mm_dvr_miso.done
);
u_async_waitrequest_n : ENTITY common_lib.common_async
GENERIC MAP (
g_rst_level => '0'
)
PORT MAP (
rst => mm_rst,
clk => mm_clk,
din => dvr_miso.waitrequest_n,
dout => mm_dvr_miso.waitrequest_n
);
mm_dvr_miso.cal_fail <= dvr_miso.cal_fail;
mm_dvr_miso.cal_ok <= dvr_miso.cal_ok;
u_cross_domain_addr : ENTITY common_lib.common_reg_cross_domain
PORT MAP (
in_rst => mm_rst,
in_clk => mm_clk,
in_dat => mm_dvr_mosi.address,
in_done => OPEN,
out_rst => dp_rst,
out_clk => dp_clk,
out_dat => dvr_mosi.address,
out_new => OPEN
);
u_cross_domain_burstsize : ENTITY common_lib.common_reg_cross_domain
PORT MAP (
in_rst => mm_rst,
in_clk => mm_clk,
in_dat => mm_dvr_mosi.burstsize,
in_done => OPEN,
out_rst => dp_rst,
out_clk => dp_clk,
out_dat => dvr_mosi.burstsize,
out_new => OPEN
);
END rtl;