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[SDRAM CMD FSM]

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- bugfix Burst mode

git-svn-id: http://moon:8086/svn/vhdl/trunk@1228 cc03376c-175c-47c8-b038-4cd826a8556b
This commit is contained in:
jens
2015-05-25 09:32:10 +00:00
parent be66661fe9
commit d0da5022ef
4 changed files with 87 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/SDRAM/ddr_sdr_v1_5/src/sdram_cmd.vhd
+30 -27
View File
@@ -51,6 +51,9 @@ end sdram_cmd;
architecture behaviour of sdram_cmd is
subtype cycle_cnt_t is natural range 0 to 15;
subtype burst_cnt_t is natural range 0 to 2**(LMR_BL_CURR)-1;
signal st_sdr, st_sdr_next : sdr_state_t;
signal cc_preset : natural range 0 to 15;
@@ -59,8 +62,7 @@ architecture behaviour of sdram_cmd is
signal burst_load_en : std_logic;
signal burst_finished : std_logic;
subtype cycle_cnt_t is natural range 0 to 15;
signal burst_cnt : burst_cnt_t;
type part_timing_array_t is array (sdr_cmd_t) of cycle_cnt_t;
constant TIMING : part_timing_array_t :=
@@ -163,36 +165,38 @@ fsm_sdr_state:
when WRITE =>
phy_ctrl.drive_en <= '1';
phy_ctrl.we <= '1';
if burst_finished = '1' then
if cmd_we = '1' and cmd = SD_WRITE then
phy_ctrl.part.addr(col_addr_t'range) <= col_addr;
cmd_ack <= '1';
phy_ctrl.part.cmd <= COMMAND(SD_NOP);
if cmd_we = '1' and cmd = SD_WRITE then
cmd_ack <= '1';
phy_ctrl.utag_we <= '1';
phy_ctrl.part.addr(col_addr_t'range) <= col_addr;
if burst_finished = '1' then
burst_load_en <= '1';
phy_ctrl.part.cmd <= COMMAND(cmd);
phy_ctrl.utag_we <= '1';
else
phy_ctrl.drive_en <= '0';
cc_load_en <= '1';
cc_preset <= TIMING(SD_WRITE)+1;
st_sdr_next <= ROW_ACT;
end if;
end if;
else
phy_ctrl.drive_en <= '0';
cc_load_en <= '1';
cc_preset <= TIMING(SD_WRITE)+1;
st_sdr_next <= ROW_ACT;
end if;
when READ =>
phy_ctrl.re <= '1';
if burst_finished = '1' then
if cmd_we = '1' and cmd = SD_READ then
phy_ctrl.part.addr(col_addr_t'range) <= col_addr;
cmd_ack <= '1';
phy_ctrl.part.cmd <= COMMAND(SD_NOP);
if cmd_we = '1' and cmd = SD_READ then
cmd_ack <= '1';
phy_ctrl.utag_we <= '1';
phy_ctrl.part.addr(col_addr_t'range) <= col_addr;
if burst_finished = '1' then
burst_load_en <= '1';
phy_ctrl.part.cmd <= COMMAND(cmd);
phy_ctrl.utag_we <= '1';
else
cc_load_en <= '1';
cc_preset <= TIMING(SD_READ);
st_sdr_next <= ROW_ACT;
end if;
end if;
else
cc_load_en <= '1';
cc_preset <= TIMING(SD_READ);
st_sdr_next <= ROW_ACT;
end if;
when WRITE_A => -- not implemented yet
cmd_ack <= '1';
@@ -265,19 +269,18 @@ cycle_counter:
------------------------------------------------------------------------------------------
burst_counter:
process (clk)
variable burst_cnt : natural range 0 to 2**(LMR_BL_CURR);
begin
if rising_edge(clk) then
if burst_load_en = '1' then
burst_finished <= '0';
burst_cnt := 2**(LMR_BL_CURR);
burst_cnt <= burst_cnt_t'high;
if 2**(LMR_BL_CURR) = DATA_RATE_FACTOR then
burst_finished <= '1';
end if;
elsif burst_cnt < DATA_RATE_FACTOR then
elsif burst_cnt <= DATA_RATE_FACTOR then
burst_finished <= '1';
else
burst_cnt := burst_cnt - DATA_RATE_FACTOR;
burst_cnt <= burst_cnt - DATA_RATE_FACTOR;
end if;
end if;
end process;
lib/SDRAM/ddr_sdr_v1_5/src/sdram_config_mt48lc16m16.vhd
+1 -1
View File
@@ -47,7 +47,7 @@ package sdram_config is
constant BIT_PRE_ALL : positive := 10; -- bit-position in column address for precharge all (see Data Sheet)
constant ENABLE_PRE_ALL : std_logic := '1';
constant ENABLE_AUTO_PRE : std_logic := '0';
constant LMR_BL_CURR : natural := LMR_BL1;
constant LMR_BL_CURR : natural := LMR_BL8;
-- DDR-SDR TIMING constants ------------------------------------------------------------------
-- After REFRESH_CLOCKS a refresh cycle is necessary, 64ms / 8192 = max every 7.8125 us refesh