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vhdl-sincos-gen
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Fix bugs in AC97 output for Atlys board. 

* Fix bugs in AC97 synchronization.
* Fix bugs in AC97 reset.
* Reduce audio volume to -12 dB.
* Set correct voltage for reset button on Atlys board.
This commit is contained in:
Joris van Rantwijk 2016-04-23 00:26:21 +02:00
parent 8bd2d389ef
commit 398dca67b6
5 changed files with 97 additions and 38 deletions
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99
synth/digilent_atlys/ac97out.vhdl
View File

@ -1,5 +1,8 @@
--
-- Simple core for AC97 audio output.
--
-- Sets output volume to -12 dB,
-- then plays stereo PCM data at 48 kHz sample rate.
-- Only tested with LM4550 on Digilent Atlys board.
--
@ -13,8 +16,8 @@ entity ac97out is
-- AC97 bit clock.
bitclk: in std_logic;
-- Synchronous reset, active high.
rst: in std_logic;
-- Asynchronous reset, active low.
resetn: in std_logic;
-- Input samples for left and right channel.
data_left: in signed(19 downto 0);
@ -25,6 +28,7 @@ entity ac97out is
data_ready: out std_logic;
-- AC97 interface signals.
ac97_sdi: in std_logic;
ac97_sdo: out std_logic;
ac97_sync: out std_logic );
@ -37,12 +41,12 @@ architecture rtl of ac97out is
constant init_table: init_table_type := (
-- write 0x0000 to register 0x00: soft reset
x"000000",
-- write 0x0000 to register 0x02: set master volume to maximum
x"020000",
-- write 0x0000 to register 0x04: set headphone volume to maximum
x"040000",
-- write 0x0000 to register 0x06: set mono_out volume to maximum
x"060000",
-- write 0x0000 to register 0x02: set master volume to -12 dB
x"020808",
-- write 0x0000 to register 0x04: set headphone volume to -12 dB
x"040808",
-- write 0x0000 to register 0x06: set mono_out volume to -12 dB
x"060008",
-- write 0x0808 to register 0x18: set PCM out volume to 0 dB
x"180808",
-- dummy read from register 0x00
@ -51,15 +55,21 @@ architecture rtl of ac97out is
x"800000" );
-- Output registers.
signal r_ready: std_logic;
signal r_sdo: std_logic;
signal r_sync: std_logic;
-- Reset synchronization.
signal r_rstsync: std_logic_vector(7 downto 0);
-- Bit counter.
signal r_bitcnt: unsigned(7 downto 0);
signal r_lastbit: std_logic;
signal r_firstbit: std_logic;
signal r_endsync: std_logic;
-- Initialization state machine.
signal r_initwait: unsigned(5 downto 0);
signal r_initbusy: std_logic;
signal r_initdone: std_logic;
signal r_initstep: unsigned(2 downto 0);
signal r_initword: std_logic_vector(23 downto 0);
@ -72,20 +82,46 @@ architecture rtl of ac97out is
-- Frame data shift register (tag + slots 1 .. 4)
signal r_sdoshift: std_logic_vector(95 downto 0);
-- AC97 bit input register
signal r_sdi: std_logic;
begin
-- Drive outputs.
data_ready <= not r_datavalid;
data_ready <= r_ready;
ac97_sdo <= r_sdo;
ac97_sync <= r_sync;
-- Synchronous process.
-- Sample AC97_SDI on falling edge of BITCLK.
process (bitclk) is
begin
if rising_edge(bitclk) then
if falling_edge(bitclk) then
r_sdi <= ac97_sdi;
end if;
end process;
-- Drive SYNC high on first bit of frame.
r_sync <= r_firstbit;
-- Synchronous process.
process (bitclk, resetn) is
begin
if resetn = '0' then
-- Asynchronous reset.
r_rstsync <= (others => '0');
r_ready <= '0';
-- Outputs to codec must be low during reset.
r_sdo <= '0';
r_sync <= '0';
elsif rising_edge(bitclk) then
-- Drive SYNC high for 16 cycles at start of frame.
if r_lastbit = '1' then
r_sync <= '1';
elsif r_endsync = '1' then
r_sync <= '0';
end if;
-- Push next data bit to output.
r_sdo <= r_sdoshift(r_sdoshift'high);
@ -108,8 +144,8 @@ begin
r_sdoshift(95) <= '1';
-- Set slots 1 and 2 valid if we are initializing.
r_sdoshift(94) <= not r_initdone;
r_sdoshift(93) <= not r_initdone;
r_sdoshift(94) <= r_initbusy;
r_sdoshift(93) <= r_initbusy;
-- Set slots 3 and 4 valid if we have valid data.
r_sdoshift(92) <= r_datavalid;
@ -122,7 +158,7 @@ begin
-- bit 19 = read (1) or write (0)
-- bit 18:12 = address
r_sdoshift(79 downto 72) <= r_initword(23 downto 16);
r_sdoshift(71 downto 0) <= (others => '0');
r_sdoshift(71 downto 60) <= (others => '0');
-- Slot 2: Register write data.
-- bit 19:4 = data
@ -130,42 +166,65 @@ begin
r_sdoshift(43 downto 40) <= (others => '0');
-- Update init pointer.
if r_initbusy = '1' then
r_initstep <= r_initstep + 1;
end if;
if r_initstep = 7 then
r_initbusy <= '0';
r_initdone <= '1';
end if;
-- Update init delay counter (wait for 1.3 ms after reset).
r_initwait <= r_initwait - 1;
if r_initwait = 0 then
r_initstep <= (others => '0');
r_initbusy <= not r_initdone;
end if;
-- Slots 3 and 4: left and right sample value.
r_sdoshift(39 downto 20) <= r_dataleft;
r_sdoshift(19 downto 0) <= r_dataright;
-- Consume sample values.
r_datavalid <= '0';
r_ready <= '1';
end if;
-- Update bit counter.
r_bitcnt <= r_bitcnt - 1;
r_firstbit <= r_lastbit;
if r_bitcnt = 1 then
r_lastbit <= '1';
else
r_lastbit <= '0';
end if;
if r_bitcnt = 241 then
r_endsync <= '1';
else
r_endsync <= '0';
end if;
-- Capture input data.
if r_datavalid = '0' and data_valid = '1' then
if r_ready = '1' and data_valid = '1' then
r_ready <= '0';
r_datavalid <= '1';
r_dataleft <= std_logic_vector(data_left);
r_dataright <= std_logic_vector(data_right);
end if;
-- Release synchronous reset.
r_rstsync <= "1" & r_rstsync(7 downto 1);
-- Synchronous reset.
if rst = '1' then
if r_rstsync(0) = '0' then
r_ready <= '0';
r_sdo <= '0';
r_sync <= '0';
r_initbusy <= '0';
r_initdone <= '0';
r_initwait <= (others => '1');
r_initstep <= (others => '0');
r_bitcnt <= (others => '0');
r_firstbit <= '0';
r_datavalid <= '0';
end if;

4
synth/digilent_atlys/atlys.ucf
View File

@ -7,7 +7,7 @@ NET "clk" TNM_NET = "clk" ;
TIMESPEC "TS_clk" = PERIOD "clk" 10 ns HIGH 50% ;
# Reset button
NET "resetn" LOC = "T15" | IOSTANDARD = LVCMOS18 ;
NET "resetn" LOC = "T15" | IOSTANDARD = LVCMOS33 ;
# LEDs
NET "led<0>" LOC = "U18" | IOSTANDARD = LVCMOS33 | SLEW = QUIETIO ;
@ -21,7 +21,7 @@ NET "led<7>" LOC = "N12" | IOSTANDARD = LVCMOS33 | SLEW = QUIETIO ;
# USB serial port J17
NET "uartrx" LOC = "A16" | IOSTANDARD = LVCMOS33 ;
NET "uarttx" LOC = "B16" | IOSTANDARD = LVCMOS33 ;
NET "uarttx" LOC = "B16" | IOSTANDARD = LVCMOS33 | SLEW = SLOW ;
# Audio
NET "ac97_bitclk" LOC = "L13" | IOSTANDARD = LVCMOS33 ;

16
synth/digilent_atlys/test_sincos.gise
View File

@ -103,7 +103,7 @@
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="ReadyToRun"/>
</transform>
<transform xil_pn:end_ts="1461346689" xil_pn:in_ck="2072574044500593778" xil_pn:name="TRANEXT_xstsynthesize_spartan6" xil_pn:prop_ck="8668749107623387584" xil_pn:start_ts="1461346674">
<transform xil_pn:end_ts="1461403854" xil_pn:in_ck="2072574044500593778" xil_pn:name="TRANEXT_xstsynthesize_spartan6" xil_pn:prop_ck="8668749107623387584" xil_pn:start_ts="1461403839">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="WarningsGenerated"/>
<status xil_pn:value="ReadyToRun"/>
@ -121,11 +121,11 @@
<outfile xil_pn:name="webtalk_pn.xml"/>
<outfile xil_pn:name="xst"/>
</transform>
<transform xil_pn:end_ts="1461346689" xil_pn:in_ck="141509727442713" xil_pn:name="TRAN_compileBCD2" xil_pn:prop_ck="7075349975164966765" xil_pn:start_ts="1461346689">
<transform xil_pn:end_ts="1461400807" xil_pn:in_ck="141509727442713" xil_pn:name="TRAN_compileBCD2" xil_pn:prop_ck="7075349975164966765" xil_pn:start_ts="1461400807">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="ReadyToRun"/>
</transform>
<transform xil_pn:end_ts="1461346696" xil_pn:in_ck="-1047380743607608193" xil_pn:name="TRANEXT_ngdbuild_FPGA" xil_pn:prop_ck="392032481918333458" xil_pn:start_ts="1461346689">
<transform xil_pn:end_ts="1461403860" xil_pn:in_ck="-1047380743607608193" xil_pn:name="TRANEXT_ngdbuild_FPGA" xil_pn:prop_ck="392032481918333458" xil_pn:start_ts="1461403854">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="ReadyToRun"/>
<outfile xil_pn:name="_ngo"/>
@ -134,10 +134,12 @@
<outfile xil_pn:name="top_test_sincos.ngd"/>
<outfile xil_pn:name="top_test_sincos_ngdbuild.xrpt"/>
</transform>
<transform xil_pn:end_ts="1461346726" xil_pn:in_ck="-1047380743607608192" xil_pn:name="TRANEXT_map_spartan6" xil_pn:prop_ck="4245753365082497697" xil_pn:start_ts="1461346696">
<transform xil_pn:end_ts="1461403888" xil_pn:in_ck="-1047380743607608192" xil_pn:name="TRANEXT_map_spartan6" xil_pn:prop_ck="4245753365082497697" xil_pn:start_ts="1461403860">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="WarningsGenerated"/>
<status xil_pn:value="ReadyToRun"/>
<status xil_pn:value="OutOfDateForOutputs"/>
<status xil_pn:value="OutputChanged"/>
<outfile xil_pn:name="_xmsgs/map.xmsgs"/>
<outfile xil_pn:name="top_test_sincos.pcf"/>
<outfile xil_pn:name="top_test_sincos_map.map"/>
@ -148,7 +150,7 @@
<outfile xil_pn:name="top_test_sincos_summary.xml"/>
<outfile xil_pn:name="top_test_sincos_usage.xml"/>
</transform>
<transform xil_pn:end_ts="1461346754" xil_pn:in_ck="693365441136831385" xil_pn:name="TRANEXT_par_spartan6" xil_pn:prop_ck="-3829590541433901613" xil_pn:start_ts="1461346726">
<transform xil_pn:end_ts="1461403915" xil_pn:in_ck="693365441136831385" xil_pn:name="TRANEXT_par_spartan6" xil_pn:prop_ck="-3829590541433901613" xil_pn:start_ts="1461403888">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="WarningsGenerated"/>
<status xil_pn:value="ReadyToRun"/>
@ -163,7 +165,7 @@
<outfile xil_pn:name="top_test_sincos_pad.txt"/>
<outfile xil_pn:name="top_test_sincos_par.xrpt"/>
</transform>
<transform xil_pn:end_ts="1461346939" xil_pn:in_ck="4016941542054796675" xil_pn:name="TRANEXT_bitFile_spartan6" xil_pn:prop_ck="97434230493978268" xil_pn:start_ts="1461346923">
<transform xil_pn:end_ts="1461403932" xil_pn:in_ck="4016941542054796675" xil_pn:name="TRANEXT_bitFile_spartan6" xil_pn:prop_ck="97434230493978268" xil_pn:start_ts="1461403915">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="WarningsGenerated"/>
<status xil_pn:value="ReadyToRun"/>
@ -176,7 +178,7 @@
<outfile xil_pn:name="webtalk.log"/>
<outfile xil_pn:name="webtalk_pn.xml"/>
</transform>
<transform xil_pn:end_ts="1461346754" xil_pn:in_ck="-1047380743607608324" xil_pn:name="TRAN_postRouteTrce" xil_pn:prop_ck="445577401284416185" xil_pn:start_ts="1461346746">
<transform xil_pn:end_ts="1461403915" xil_pn:in_ck="-1047380743607608324" xil_pn:name="TRAN_postRouteTrce" xil_pn:prop_ck="445577401284416185" xil_pn:start_ts="1461403907">
<status xil_pn:value="SuccessfullyRun"/>
<status xil_pn:value="WarningsGenerated"/>
<status xil_pn:value="ReadyToRun"/>

1
synth/digilent_atlys/test_sincos.xise
View File

@ -246,6 +246,7 @@
<property xil_pn:name="Preferred Language" xil_pn:value="VHDL" xil_pn:valueState="non-default"/>
<property xil_pn:name="Produce Verbose Report" xil_pn:value="false" xil_pn:valueState="default"/>
<property xil_pn:name="Project Description" xil_pn:value="" xil_pn:valueState="default"/>
<property xil_pn:name="Project Generator" xil_pn:value="ProjNav" xil_pn:valueState="default"/>
<property xil_pn:name="Property Specification in Project File" xil_pn:value="Store all values" xil_pn:valueState="default"/>
<property xil_pn:name="RAM Extraction" xil_pn:value="true" xil_pn:valueState="default"/>
<property xil_pn:name="RAM Style" xil_pn:value="Auto" xil_pn:valueState="default"/>

13
synth/digilent_atlys/top_test_sincos.vhdl
View File

@ -73,7 +73,6 @@ architecture rtl of top_test_sincos is
signal r_ac97_rstcnt: unsigned(7 downto 0);
signal r_ac97_rst: std_logic;
signal r_ac97_rstsync: std_logic_vector(7 downto 0);
signal r_ac97_phase: unsigned(19 downto 0);
signal s_ac97_sine: signed(17 downto 0);
signal s_ac97_dataleft: signed(19 downto 0);
@ -109,14 +108,16 @@ begin
u2: entity work.ac97out
port map (
bitclk => ac97_bitclk,
rst => r_ac97_rstsync(0),
resetn => r_ac97_rst,
data_left => s_ac97_dataleft,
data_right => s_ac97_dataright,
data_valid => '1',
data_ready => s_ac97_ready,
ac97_sdi => ac97_sdi,
ac97_sdo => ac97_sdo,
ac97_sync => ac97_sync );
-- Pad 18-bit signed samples to 20-bit.
s_ac97_dataleft <= s_ac97_sine & "00";
s_ac97_dataright <= s_ac97_sine & "00";
@ -157,13 +158,9 @@ begin
end process;
-- Synchronous process in AC97 bitclock domain.
process (ac97_bitclk, r_ac97_rst) is
process (ac97_bitclk) is
begin
if r_ac97_rst = '0' then
r_ac97_rstsync <= (others => '1');
r_ac97_phase <= (others => '0');
elsif rising_edge(ac97_bitclk) then
r_ac97_rstsync <= "0" & r_ac97_rstsync(7 downto 1);
if rising_edge(ac97_bitclk) then
if s_ac97_ready = '1' then
r_ac97_phase <= r_ac97_phase + tone_freq;
end if;