diff options
Diffstat (limited to 'debugger.vhd')
| -rw-r--r-- | debugger.vhd | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/debugger.vhd b/debugger.vhd index bf82850..9d842e2 100644 --- a/debugger.vhd +++ b/debugger.vhd @@ -21,12 +21,19 @@ port ( CLKEN_IN : in std_logic;
-- Gated clock enable back out to CPU
CLKEN_OUT : out std_logic;
+ -- CPU IRQ in
+ nIRQ_IN : in std_logic;
+ -- Gated IRQ back out to CPU (no interrupts when single stepping)
+ nIRQ_OUT : out std_logic;
-- CPU
A_CPU : in std_logic_vector(15 downto 0);
R_nW : in std_logic;
SYNC : in std_logic;
+ -- Aux bus input for display in hex
+ AUX_BUS : in std_logic_vector(15 downto 0);
+
-- Controls
-- RUN or HALT CPU
RUN : in std_logic;
@@ -60,7 +67,7 @@ port ( end component;
-- Current display mode
-type mode_t is (modeAddress,modeBreak,modeWatch);
+type mode_t is (modeAddress,modeBreak,modeWatch,modeAux);
signal mode : mode_t;
-- Current edit digit
signal digit : unsigned(1 downto 0);
@@ -95,11 +102,14 @@ signal r_set_n : std_logic; begin
-- Mask CPU clock enable
CLKEN_OUT <= CLKEN_IN and not halt;
+ -- Mask interrupt
+ nIRQ_OUT <= nIRQ_IN or not RUN;
-- Route selected address to display
a_display <= instr_addr when mode = modeAddress else
breakpoint when mode = modeBreak else
watchpoint when mode = modeWatch else
+ AUX_BUS when mode = modeAux else
(others => '0');
-- Generate display digits from binary
@@ -109,14 +119,14 @@ begin d0 : seg7 port map (a_display(3 downto 0),d0_display);
-- Flash selected digit in edit modes
- DIGIT3 <= d3_display when (mode = modeAddress or flash = '1' or digit /= "11") else "1111111";
- DIGIT2 <= d2_display when (mode = modeAddress or flash = '1' or digit /= "10") else "1111111";
- DIGIT1 <= d1_display when (mode = modeAddress or flash = '1' or digit /= "01") else "1111111";
- DIGIT0 <= d0_display when (mode = modeAddress or flash = '1' or digit /= "00") else "1111111";
+ DIGIT3 <= d3_display when (mode = modeAddress or mode = modeAux or flash = '1' or digit /= "11") else "1111111";
+ DIGIT2 <= d2_display when (mode = modeAddress or mode = modeAux or flash = '1' or digit /= "10") else "1111111";
+ DIGIT1 <= d1_display when (mode = modeAddress or mode = modeAux or flash = '1' or digit /= "01") else "1111111";
+ DIGIT0 <= d0_display when (mode = modeAddress or mode = modeAux or flash = '1' or digit /= "00") else "1111111";
-- Show mode on LEDs
- LED_BREAKPOINT <= '1' when mode = modeBreak else '0';
- LED_WATCHPOINT <= '1' when mode = modeWatch else '0';
+ LED_BREAKPOINT <= '1' when mode = modeBreak or mode = modeAux else '0';
+ LED_WATCHPOINT <= '1' when mode = modeWatch or mode = modeAux else '0';
-- Flash counter
process(CLOCK,nRESET)
@@ -153,6 +163,8 @@ begin mode <= modeBreak;
elsif mode = modeBreak then
mode <= modeWatch;
+ elsif mode = modeWatch then
+ mode <= modeAux;
else
mode <= modeAddress;
end if;
@@ -215,6 +227,11 @@ begin -- Register single-step button
r_step_n <= nSTEP;
+ -- Once the CPU has run we can trigger a new halt
+ if CLKEN_IN = '1' then
+ resuming <= '0';
+ end if;
+
if SYNC = '1' then
-- Latch address of instruction fetch
instr_addr <= A_CPU;
@@ -242,11 +259,6 @@ begin resuming <= '1';
halt <= '0';
end if;
-
- -- Once the CPU has run we can trigger a new halt
- if CLKEN_IN = '1' then
- resuming <= '0';
- end if;
end if;
end process;
end architecture;
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