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Registers.vhd added

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Florian Reitz 2019-04-08 21:17:44 +02:00
parent 26909735ae
commit f94c55322d
4 changed files with 315 additions and 233 deletions
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113
VHDL/AppleIISd.vhd
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@ -68,28 +68,58 @@ architecture Behavioral of AppleIISd is
signal data_in : std_logic_vector (7 downto 0); signal data_in : std_logic_vector (7 downto 0);
signal data_out : std_logic_vector (7 downto 0); signal data_out : std_logic_vector (7 downto 0);
signal addr_low_int : std_logic_vector (1 downto 0); signal addr_low_int : std_logic_vector (1 downto 0);
signal s_spi_data_in : std_logic_vector(7 downto 0);
signal s_spi_data_out : std_logic_vector(7 downto 0);
signal s_bsy : std_logic;
signal s_tc : std_logic;
signal s_ece : std_logic;
signal s_frx : std_logic;
signal data_en : std_logic; signal data_en : std_logic;
signal pgm_en : std_logic; signal pgm_en : std_logic;
component Registers is
Port (
ADDR : in STD_LOGIC_VECTOR (1 downto 0);
BUS_DATA_IN : in STD_LOGIC_VECTOR (7 downto 0);
BUS_DATA_OUT : out STD_LOGIC_VECTOR (7 downto 0);
SPI_DATA_IN : in STD_LOGIC_VECTOR (7 downto 0);
SPI_DATA_OUT : out STD_LOGIC_VECTOR (7 downto 0);
PGMEN : out STD_LOGIC;
ECE : out STD_LOGIC;
FRX : out STD_LOGIC;
SLAVESEL : out STD_LOGIC;
LED : out STD_LOGIC;
BSY : in STD_LOGIC;
TC : in STD_LOGIC;
WP : in STD_LOGIC;
CARD : in STD_LOGIC;
NRESET : in STD_LOGIC;
NDEV_SEL : in STD_LOGIC;
IS_READ : in STD_LOGIC
);
end component;
component SpiController is component SpiController is
Port ( Port (
data_in : in std_logic_vector (7 downto 0); BUS_DATA : in STD_LOGIC_VECTOR (7 downto 0);
data_out : out std_logic_vector (7 downto 0); SPI_DATA : out STD_LOGIC_VECTOR (7 downto 0);
is_read : in std_logic; IS_READ : in STD_LOGIC;
nreset : in std_logic; NRESET : in STD_LOGIC;
addr : in std_logic_vector (1 downto 0); ADDR : in STD_LOGIC_VECTOR (1 downto 0);
phi0 : in std_logic; CLK_SLOW : in STD_LOGIC;
ndev_sel : in std_logic; NDEV_SEL : in STD_LOGIC;
clk : in std_logic; CLK_FAST : in STD_LOGIC;
miso: in std_logic; MISO: in std_logic;
mosi : out std_logic; MOSI : out STD_LOGIC;
sclk : out std_logic; SCLK : out STD_LOGIC;
nsel : out std_logic;
wp : in std_logic; BSY : out STD_LOGIC;
card : in std_logic; TC : out STD_LOGIC;
led : out std_logic; FRX : in std_logic;
pgm_en : out std_logic ECE : in std_logic
); );
end component; end component;
@ -114,23 +144,42 @@ end component;
begin begin
regs: Registers port map(
ADDR => addr_low_int,
BUS_DATA_IN => data_in,
BUS_DATA_OUT => data_out,
SPI_DATA_IN => s_spi_data_in,
SPI_DATA_OUT => s_spi_data_out,
PGMEN => pgm_en,
ECE => s_ece,
FRX => s_frx,
SLAVESEL => NSEL,
LED => LED,
BSY => s_bsy,
TC => s_tc,
WP => WP,
CARD => CARD,
NRESET => NRESET,
NDEV_SEL => NDEV_SEL,
IS_READ => RNW
);
spi: SpiController port map( spi: SpiController port map(
data_in => data_in, BUS_DATA => s_spi_data_out,
data_out => data_out, SPI_DATA => s_spi_data_in,
is_read => RNW, IS_READ => RNW,
nreset => NRESET, NRESET => NRESET,
addr => addr_low_int, ADDR => addr_low_int,
phi0 => PHI0, CLK_SLOW => PHI0,
ndev_sel => NDEV_SEL, CLK_FAST => CLK,
clk => CLK, NDEV_SEL => NDEV_SEL,
miso => MISO, MISO => MISO,
mosi => MOSI, MOSI => MOSI,
sclk => SCLK, SCLK => SCLK,
nsel => NSEL, BSY => s_bsy,
wp => WP, TC => s_tc,
card => CARD, FRX => s_frx,
led => LED, ECE => s_ece
pgm_en => pgm_en
); );
addDec: AddressDecoder port map( addDec: AddressDecoder port map(

12
VHDL/AppleIISd_PC44.xise
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@ -24,7 +24,7 @@
</file> </file>
<file xil_pn:name="AppleIISd.vhd" xil_pn:type="FILE_VHDL"> <file xil_pn:name="AppleIISd.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/> <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/>
<association xil_pn:name="Implementation" xil_pn:seqID="3"/> <association xil_pn:name="Implementation" xil_pn:seqID="4"/>
</file> </file>
<file xil_pn:name="AppleIISd_Test.vhd" xil_pn:type="FILE_VHDL"> <file xil_pn:name="AppleIISd_Test.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/> <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/>
@ -32,12 +32,16 @@
</file> </file>
<file xil_pn:name="AddressDecoder.vhd" xil_pn:type="FILE_VHDL"> <file xil_pn:name="AddressDecoder.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="1"/> <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="1"/>
<association xil_pn:name="Implementation" xil_pn:seqID="2"/> <association xil_pn:name="Implementation" xil_pn:seqID="3"/>
</file> </file>
<file xil_pn:name="AddressDecoder_Test.vhd" xil_pn:type="FILE_VHDL"> <file xil_pn:name="AddressDecoder_Test.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="2"/> <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="2"/>
<association xil_pn:name="PostRouteSimulation" xil_pn:seqID="230"/> <association xil_pn:name="PostRouteSimulation" xil_pn:seqID="230"/>
</file> </file>
<file xil_pn:name="Registers.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="56"/>
<association xil_pn:name="Implementation" xil_pn:seqID="2"/>
</file>
</files> </files>
<properties> <properties>
@ -105,7 +109,7 @@
<property xil_pn:name="Launch SDK after Export" xil_pn:value="true" xil_pn:valueState="default"/> <property xil_pn:name="Launch SDK after Export" xil_pn:value="true" xil_pn:valueState="default"/>
<property xil_pn:name="Library for Verilog Sources" xil_pn:value="" xil_pn:valueState="default"/> <property xil_pn:name="Library for Verilog Sources" xil_pn:value="" xil_pn:valueState="default"/>
<property xil_pn:name="Load glbl" xil_pn:value="true" xil_pn:valueState="default"/> <property xil_pn:name="Load glbl" xil_pn:value="true" xil_pn:valueState="default"/>
<property xil_pn:name="Logic Optimization" xil_pn:value="Speed" xil_pn:valueState="default"/> <property xil_pn:name="Logic Optimization" xil_pn:value="Density" xil_pn:valueState="non-default"/>
<property xil_pn:name="Macro Preserve" xil_pn:value="true" xil_pn:valueState="default"/> <property xil_pn:name="Macro Preserve" xil_pn:value="true" xil_pn:valueState="default"/>
<property xil_pn:name="Macrocell Power Setting" xil_pn:value="Std" xil_pn:valueState="default"/> <property xil_pn:name="Macrocell Power Setting" xil_pn:value="Std" xil_pn:valueState="default"/>
<property xil_pn:name="Manual Implementation Compile Order" xil_pn:value="false" xil_pn:valueState="default"/> <property xil_pn:name="Manual Implementation Compile Order" xil_pn:value="false" xil_pn:valueState="default"/>
@ -114,7 +118,7 @@
<property xil_pn:name="Mux Extraction" xil_pn:value="Yes" xil_pn:valueState="default"/> <property xil_pn:name="Mux Extraction" xil_pn:value="Yes" xil_pn:valueState="default"/>
<property xil_pn:name="Netlist Hierarchy" xil_pn:value="As Optimized" xil_pn:valueState="default"/> <property xil_pn:name="Netlist Hierarchy" xil_pn:value="As Optimized" xil_pn:valueState="default"/>
<property xil_pn:name="Optimization Effort" xil_pn:value="Normal" xil_pn:valueState="default"/> <property xil_pn:name="Optimization Effort" xil_pn:value="Normal" xil_pn:valueState="default"/>
<property xil_pn:name="Optimization Goal" xil_pn:value="Speed" xil_pn:valueState="default"/> <property xil_pn:name="Optimization Goal" xil_pn:value="Area" xil_pn:valueState="non-default"/>
<property xil_pn:name="Other CPLD Fitter Command Line Options" xil_pn:value="" xil_pn:valueState="default"/> <property xil_pn:name="Other CPLD Fitter Command Line Options" xil_pn:value="" xil_pn:valueState="default"/>
<property xil_pn:name="Other Compiler Options" xil_pn:value="" xil_pn:valueState="default"/> <property xil_pn:name="Other Compiler Options" xil_pn:value="" xil_pn:valueState="default"/>
<property xil_pn:name="Other Compiler Options Fit" xil_pn:value="" xil_pn:valueState="default"/> <property xil_pn:name="Other Compiler Options Fit" xil_pn:value="" xil_pn:valueState="default"/>

138
VHDL/Registers.vhd Normal file
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@ -0,0 +1,138 @@
----------------------------------------------------------------------------------
-- Company:
-- Engineer:
--
-- Create Date: 20:04:43 04/08/2019
-- Design Name:
-- Module Name: Registers - Behavioral
-- Project Name:
-- Target Devices:
-- Tool versions:
-- Description:
--
-- Dependencies:
--
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
--
----------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--use IEEE.NUMERIC_STD.ALL;
-- Uncomment the following library declaration if instantiating
-- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;
entity Registers is
Port ( ADDR : in STD_LOGIC_VECTOR (1 downto 0);
BUS_DATA_IN : in STD_LOGIC_VECTOR (7 downto 0);
BUS_DATA_OUT : out STD_LOGIC_VECTOR (7 downto 0);
SPI_DATA_IN : in STD_LOGIC_VECTOR (7 downto 0);
SPI_DATA_OUT : out STD_LOGIC_VECTOR (7 downto 0);
PGMEN : out STD_LOGIC;
ECE : out STD_LOGIC;
FRX : out STD_LOGIC;
SLAVESEL : out STD_LOGIC;
LED : out STD_LOGIC;
BSY : in STD_LOGIC;
TC : in STD_LOGIC;
WP : in STD_LOGIC;
CARD : in STD_LOGIC;
NRESET : in STD_LOGIC;
NDEV_SEL : in STD_LOGIC;
IS_READ : in STD_LOGIC);
end Registers;
architecture Behavioral of Registers is
signal s_pgmen : STD_LOGIC;
signal s_ece : STD_LOGIC;
signal s_frx : STD_LOGIC;
signal s_slavesel : STD_LOGIC;
signal s_sdhc : STD_LOGIC;
signal s_inited : STD_LOGIC;
begin
PGMEN <= s_pgmen;
ECE <= s_ece;
FRX <= s_frx;
SLAVESEL <= s_slavesel;
LED <= not (BSY or not s_slavesel);
--------------------------
-- cpu register section
-- cpu read
cpu_read: process(ADDR, SPI_DATA_IN, tc, bsy, s_frx, s_pgmen,
s_ece, s_slavesel, wp, CARD, s_sdhc, s_inited)
begin
case ADDR is
when "00" => -- read SPI data in
BUS_DATA_OUT <= SPI_DATA_IN;
when "01" => -- read status register
BUS_DATA_OUT(0) <= s_pgmen;
BUS_DATA_OUT(1) <= '0';
BUS_DATA_OUT(2) <= s_ece;
BUS_DATA_OUT(3) <= '0';
BUS_DATA_OUT(4) <= s_frx;
BUS_DATA_OUT(5) <= BSY;
BUS_DATA_OUT(6) <= '0';
BUS_DATA_OUT(7) <= TC;
-- "10" is unused
when "11" => -- read slave select / slave interrupt state
BUS_DATA_OUT(0) <= s_slavesel;
BUS_DATA_OUT(3 downto 1) <= (others => '0');
BUS_DATA_OUT(4) <= s_sdhc;
BUS_DATA_OUT(5) <= WP;
BUS_DATA_OUT(6) <= CARD;
BUS_DATA_OUT(7) <= s_inited;
when others =>
BUS_DATA_OUT <= (others => '0');
end case;
end process;
-- cpu write
cpu_write: process(NRESET, NDEV_SEL, IS_READ, ADDR, BUS_DATA_IN, CARD)
begin
if (NRESET = '0') then
s_ece <= '0';
s_frx <= '0';
s_slavesel <= '1';
SPI_DATA_OUT <= (others => '1');
s_sdhc <= '0';
s_inited <= '0';
s_pgmen <= '0';
elsif (CARD = '1') then
s_sdhc <= '0';
s_inited <= '0';
elsif (rising_edge(NDEV_SEL) and IS_READ = '0') then
case ADDR is
when "00" => -- write SPI data out (see other process above)
SPI_DATA_OUT <= BUS_DATA_IN;
when "01" => -- write status register
s_pgmen <= BUS_DATA_IN(0);
s_ece <= BUS_DATA_IN(2);
s_frx <= BUS_DATA_IN(4);
-- no bit 5 - 7
-- "10" is unused
when "11" => -- write slave select / slave interrupt enable
s_slavesel <= BUS_DATA_IN(0);
-- no bit 1 - 3
s_sdhc <= BUS_DATA_IN(4);
-- no bit 5 - 6
s_inited <= BUS_DATA_IN(7);
when others =>
end case;
end if;
end process;
end Behavioral;

285
VHDL/SpiController.vhd
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@ -11,26 +11,24 @@ use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity SpiController is entity SpiController is
Port ( Port (
data_in : in STD_LOGIC_VECTOR (7 downto 0); BUS_DATA : in STD_LOGIC_VECTOR (7 downto 0);
data_out : out STD_LOGIC_VECTOR (7 downto 0); SPI_DATA : out STD_LOGIC_VECTOR (7 downto 0);
is_read : in STD_LOGIC; IS_READ : in STD_LOGIC;
nreset : in STD_LOGIC; NRESET : in STD_LOGIC;
addr : in STD_LOGIC_VECTOR (1 downto 0); ADDR : in STD_LOGIC_VECTOR (1 downto 0);
phi0 : in STD_LOGIC; CLK_SLOW : in STD_LOGIC;
ndev_sel : in STD_LOGIC; CLK_FAST : in STD_LOGIC;
clk : in STD_LOGIC; NDEV_SEL : in STD_LOGIC;
miso: in std_logic; MISO: in std_logic;
mosi : out STD_LOGIC; MOSI : out STD_LOGIC;
sclk : out STD_LOGIC; SCLK : out STD_LOGIC;
nsel : out STD_LOGIC;
wp : in STD_LOGIC; BSY : out STD_LOGIC;
card : in STD_LOGIC; TC : out STD_LOGIC;
pgm_en : out STD_LOGIC; FRX : in std_logic;
led : out STD_LOGIC ECE : in std_logic
); );
constant DIV_WIDTH : integer := 3;
end SpiController; end SpiController;
architecture Behavioral of SpiController is architecture Behavioral of SpiController is
@ -38,115 +36,109 @@ architecture Behavioral of SpiController is
-------------------------- --------------------------
-- internal state -- internal state
signal spidatain: std_logic_vector (7 downto 0); signal spidatain: std_logic_vector (7 downto 0);
signal spidataout: std_logic_vector (7 downto 0);
signal sdhc: std_logic; -- is SDHC card
signal inited: std_logic; -- card initialized
signal pgmen: std_logic; -- enable EEPROM programming
-- spi register flags
signal tc: std_logic; -- transmission complete; cleared on spi data read
signal bsy: std_logic; -- SPI busy
signal frx: std_logic; -- fast receive mode
signal ece: std_logic; -- external clock enable; 0=phi2, 1=external clock
signal divisor: std_logic_vector(DIV_WIDTH-1 downto 0);
signal slavesel: std_logic := '1'; -- slave select output (0=selected)
signal int_miso: std_logic;
-------------------------- --------------------------
-- helper signals -- helper signals
-- shift engine -- shift engine
signal start_shifting: std_logic := '0'; -- shifting data signal s_start_shifting: std_logic := '0'; -- shifting data
signal shifting2: std_logic := '0'; -- shifting data signal s_shifting2: std_logic := '0'; -- shifting data
signal shiftdone: std_logic; -- shifting data done signal s_shiftdone: std_logic; -- shifting data done
signal shiftcnt: std_logic_vector(3 downto 0); -- shift counter (5 bit) signal s_shiftcnt: std_logic_vector(3 downto 0); -- shift counter (5 bit)
-- spi clock -- spi clock
signal clksrc: std_logic; -- clock source (phi2 or clk_7m) signal s_clksrc: std_logic; -- clock source (phi2 or clk_7m)
-- TODO divcnt is not used at all?? signal s_shiftclk : std_logic;
--signal divcnt: std_logic_vector(DIV_WIDTH-1 downto 0); -- divisor counter
signal shiftclk : std_logic;
begin begin
led <= not (bsy or not slavesel); --------------------------
bsy <= start_shifting or shifting2; -- spiclk - spi clock generation
-- spiclk is still 2 times the freq. than SCLK
s_clksrc <= CLK_SLOW when (ECE = '0') else CLK_FAST;
process(start_shifting, shiftdone, shiftclk) -- is a pulse signal to allow for divisor==0
s_shiftclk <= s_clksrc when (s_start_shifting or s_shifting2) = '1' else '0';
BSY <= s_start_shifting or s_shifting2;
SPI_DATA <= spidatain;
process(s_start_shifting, s_shiftdone, s_shiftclk)
begin begin
if (rising_edge(shiftclk)) then if (rising_edge(s_shiftclk)) then
if (shiftdone = '1') then if (s_shiftdone = '1') then
shifting2 <= '0'; s_shifting2 <= '0';
else else
shifting2 <= start_shifting; s_shifting2 <= s_start_shifting;
end if; end if;
end if; end if;
end process; end process;
process(shiftcnt, nreset, shiftclk) process(s_shiftcnt, NRESET, s_shiftclk)
begin begin
if (nreset = '0') then if (NRESET = '0') then
shiftdone <= '0'; s_shiftdone <= '0';
elsif (rising_edge(shiftclk)) then elsif (rising_edge(s_shiftclk)) then
if (shiftcnt = "1111") then if (s_shiftcnt = "1111") then
shiftdone <= '1'; s_shiftdone <= '1';
else else
shiftdone <= '0'; s_shiftdone <= '0';
end if; end if;
end if; end if;
end process; end process;
process(nreset, shifting2, shiftcnt, shiftclk) process(NRESET, s_shifting2, s_shiftcnt, s_shiftclk)
begin begin
if (nreset = '0') then if (NRESET = '0') then
shiftcnt <= (others => '0'); s_shiftcnt <= (others => '0');
elsif (rising_edge(shiftclk)) then elsif (rising_edge(s_shiftclk)) then
if (shifting2 = '1') then if (s_shifting2 = '1') then
-- count phase -- count phase
shiftcnt <= shiftcnt + 1; s_shiftcnt <= s_shiftcnt + 1;
else else
shiftcnt <= (others => '0'); s_shiftcnt <= (others => '0');
end if; end if;
end if; end if;
end process; end process;
inproc: process(nreset, shifting2, shiftcnt, shiftclk, spidatain, miso) inproc: process(NRESET, s_shifting2, s_shiftcnt, s_shiftclk, spidatain, miso)
begin begin
if (nreset = '0') then if (NRESET = '0') then
spidatain <= (others => '0'); spidatain <= (others => '0');
elsif (rising_edge(shiftclk)) then elsif (rising_edge(s_shiftclk)) then
if (shifting2 = '1' and shiftcnt(0) = '1') then if (s_shifting2 = '1' and s_shiftcnt(0) = '1') then
-- shift in to input register -- shift in to input register
spidatain (7 downto 1) <= spidatain (6 downto 0); spidatain (7 downto 1) <= spidatain (6 downto 0);
spidatain (0) <= int_miso; spidatain (0) <= MISO;
end if; end if;
end if; end if;
end process; end process;
outproc: process(nreset, shifting2, spidataout, shiftcnt, shiftclk) outproc: process(NRESET, s_shifting2, BUS_DATA, s_shiftcnt, s_shiftclk)
begin begin
if (nreset = '0') then if (NRESET = '0') then
mosi <= '1'; MOSI <= '1';
sclk <= '1'; SCLK <= '1';
else else
-- clock is sync'd -- clock is sync'd
if (rising_edge(shiftclk)) then if (rising_edge(s_shiftclk)) then
if (shifting2='0' or shiftdone = '1') then if (s_shifting2='0' or s_shiftdone = '1') then
mosi <= '1'; MOSI <= '1';
sclk <= '1'; SCLK <= '1';
else else
-- output data directly from output register -- output data directly from output register
case shiftcnt(3 downto 1) is case s_shiftcnt(3 downto 1) is
when "000" => mosi <= spidataout(7); when "000" => MOSI <= BUS_DATA(7);
when "001" => mosi <= spidataout(6); when "001" => MOSI <= BUS_DATA(6);
when "010" => mosi <= spidataout(5); when "010" => MOSI <= BUS_DATA(5);
when "011" => mosi <= spidataout(4); when "011" => MOSI <= BUS_DATA(4);
when "100" => mosi <= spidataout(3); when "100" => MOSI <= BUS_DATA(3);
when "101" => mosi <= spidataout(2); when "101" => MOSI <= BUS_DATA(2);
when "110" => mosi <= spidataout(1); when "110" => MOSI <= BUS_DATA(1);
when "111" => mosi <= spidataout(0); when "111" => MOSI <= BUS_DATA(0);
when others => mosi <= '1'; when others => MOSI <= '1';
end case; end case;
sclk <= shiftcnt(0); SCLK <= s_shiftcnt(0);
end if; end if;
end if; end if;
end if; end if;
@ -154,125 +146,24 @@ begin
-- shift operation enable -- shift operation enable
shiften: process(nreset, ndev_sel, is_read, addr, frx, shiftdone) shiften: process(NRESET, NDEV_SEL, IS_READ, ADDR, FRX, s_shiftdone)
begin begin
-- start shifting -- start shifting
if (nreset = '0' or shiftdone = '1') then if (NRESET = '0' or s_shiftdone = '1') then
start_shifting <= '0'; s_start_shifting <= '0';
elsif (rising_edge(ndev_sel) and addr="00" and (frx='1' or is_read='0')) then elsif (rising_edge(NDEV_SEL) and ADDR="00" and (FRX='1' or IS_READ='0')) then
-- access to register 00, either write (is_read=0) or fast receive bit set (frx) -- access to register 00, either write (IS_READ=0) or fast receive bit set (frx)
-- then both types of access (write but also read) -- then both types of access (write but also read)
start_shifting <= '1'; s_start_shifting <= '1';
end if;
end process;
--------------------------
-- spiclk - spi clock generation
-- spiclk is still 2 times the freq. than sclk
clksrc <= phi0 when (ece = '0') else clk;
-- is a pulse signal to allow for divisor==0
--shiftclk <= clksrc when divcnt = "000000" else '0';
shiftclk <= clksrc when bsy = '1' else '0';
-- clkgen: process(nreset, divisor, clksrc)
-- begin
-- if (nreset = '0') then
-- divcnt <= divisor;
-- elsif (falling_edge(clksrc)) then
-- if (shiftclk = '1') then
-- divcnt <= divisor;
-- else
-- divcnt <= divcnt - 1;
-- end if;
-- end if;
-- end process;
--------------------------
-- interface section
-- inputs
int_miso <= (miso and not slavesel);
-- outputs
nsel <= slavesel;
pgm_en <= pgmen;
tc_proc: process (ndev_sel, shiftdone)
begin
if (shiftdone = '1') then
tc <= '1';
elsif (rising_edge(ndev_sel) and addr="00") then
tc <= '0';
end if; end if;
end process; end process;
-------------------------- tc_proc: process (NDEV_SEL, s_shiftdone)
-- cpu register section
-- cpu read
cpu_read: process(addr, spidatain, tc, bsy, frx, pgmen,
ece, divisor, slavesel, wp, card, sdhc, inited)
begin begin
case addr is if (s_shiftdone = '1') then
when "00" => -- read SPI data in TC <= '1';
data_out <= spidatain; elsif (rising_edge(NDEV_SEL) and ADDR="00") then
when "01" => -- read status register TC <= '0';
data_out(0) <= pgmen;
data_out(1) <= '0';
data_out(2) <= ece;
data_out(3) <= '0';
data_out(4) <= frx;
data_out(5) <= bsy;
data_out(6) <= '0';
data_out(7) <= tc;
when "10" => -- read sclk divisor
data_out(DIV_WIDTH-1 downto 0) <= divisor;
data_out(7 downto 3) <= (others => '0');
when "11" => -- read slave select / slave interrupt state
data_out(0) <= slavesel;
data_out(3 downto 1) <= (others => '0');
data_out(4) <= sdhc;
data_out(5) <= wp;
data_out(6) <= card;
data_out(7) <= inited;
when others =>
data_out <= (others => '0');
end case;
end process;
-- cpu write
cpu_write: process(nreset, ndev_sel, is_read, addr, data_in, card)
begin
if (nreset = '0') then
ece <= '0';
frx <= '0';
slavesel <= '1';
divisor <= (others => '0');
spidataout <= (others => '1');
sdhc <= '0';
inited <= '0';
pgmen <= '0';
elsif (card = '1') then
sdhc <= '0';
inited <= '0';
elsif (rising_edge(ndev_sel) and is_read = '0') then
case addr is
when "00" => -- write SPI data out (see other process above)
spidataout <= data_in;
when "01" => -- write status register
pgmen <= data_in(0);
ece <= data_in(2);
frx <= data_in(4);
-- no bit 5 - 7
when "10" => -- write divisor
divisor <= data_in(DIV_WIDTH-1 downto 0);
when "11" => -- write slave select / slave interrupt enable
slavesel <= data_in(0);
-- no bit 1 - 3
sdhc <= data_in(4);
-- no bit 5 - 6
inited <= data_in(7);
when others =>
end case;
end if; end if;
end process; end process;