diff options
Diffstat (limited to 'zpu/hdl/zpu4/src')
| -rw-r--r-- | zpu/hdl/zpu4/src/io.vhd | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/zpu/hdl/zpu4/src/io.vhd b/zpu/hdl/zpu4/src/io.vhd index 9e65929..f71f51d 100644 --- a/zpu/hdl/zpu4/src/io.vhd +++ b/zpu/hdl/zpu4/src/io.vhd @@ -37,6 +37,7 @@ signal timer_we : std_logic; signal serving : std_logic;
file l_file : TEXT open write_mode is log_file;
+constant lowAddrBits: std_logic_vector(minAddrBit-1 downto 0) := (others=>'0');
begin
@@ -54,42 +55,50 @@ begin process(areset, clk)
begin
+ taddr := (others => '0');
+ taddr(maxAddrBit downto minAddrBit) := addr;
+
if (areset = '1') then
-- timer_we <= '0';
elsif (clk'event and clk = '1') then
-- timer_we <= '0';
if writeEnable = '1' then
- -- external interface (fixed address) - --<JK> extend compare to avoid waring messages - if ("000" & addr)=x"2028003" then + -- external interface (fixed address)
+ --<JK> extend compare to avoid waring messages
+ if ("1" & addr & lowAddrBits)=x"80a000c" then
+ report "Write to UART[0]" & " :0x" & hstr(write);
-- Write to UART
-- report "" & character'image(conv_integer(memBint)) severity note;
print(l_file, character'val(to_integer(unsigned(write))));
elsif addr(12)='1' then
+ report "Write to TIMER" & " :0x" & hstr(write);
-- report "xxx" severity failure;
-- timer_we <= '1';
else
print(l_file, character'val(to_integer(unsigned(write))));
- -- report "Illegal IO write" severity warning; + report "Illegal IO write @" & "0x" & hstr(taddr) severity warning;
end if;
end if;
read <= (others => '0');
if (readEnable = '1') then
- --<JK> extend compare to avoid waring messages - if ("000" & addr)=x"0001001" then - read <= (0=>'1', others => '0'); -- recieve empty
+ --<JK> extend compare to avoid waring messages
+ if ("1" & addr & lowAddrBits)=x"80a000c" then
+ report "Read UART[0]";
+ read(8) <= '0'; -- output fifo not full
+ read(9) <= '1'; -- receiver not empty
+ elsif ("1" & addr & lowAddrBits)=x"80a0010" then
+ report "Read UART[1]";
+ read(8) <= '1'; -- receiver not empty
+ read(7 downto 0) <= (others => '0');
elsif addr(12)='1' then
+ report "Read TIMER";
read(7 downto 0) <= timer_read;
elsif addr(11)='1' then
+ report "Read ZPU Freq";
read(7 downto 0) <= ZPU_Frequency;
- --<JK> extend compare to avoid waring messages - elsif ("000" & addr)=x"2028003" then - read <= (others => '0');
else
- read <= (others => '0');
- read(8) <= '1';
- -- report "Illegal IO read" severity warning; + report "Illegal IO read @" & "0x" & hstr(taddr) severity warning;
end if;
end if;
end if;
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