z80ctc wip

floooh · Jul 14, 2024 · 1a056c5 · 1a056c5
1 parent 8d43c17
commit 1a056c5
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Showing 2 changed files with 55 additions and 7 deletions.
diff --git a/src/chips/z80ctc.zig b/src/chips/z80ctc.zig
@@ -174,10 +174,10 @@ pub fn Z80CTC(comptime P: Pins, comptime Bus: anytype) type {
             var bus = in_bus;
             const data = getData(bus);
             const chn_id: usize = (bus >> P.CS[0]) & 3;
-            var chn = self.chn[chn_id];
+            var chn = &self.chn[chn_id];
             if (chn.control & CTRL.CONST_FOLLOWS != 0) {
                 // timer constant following control word
-                chn.control &= ~(CTRL.CONST_FOLLOW | CTRL.RESET);
+                chn.control &= ~(CTRL.CONST_FOLLOWS | CTRL.RESET);
                 chn.constant = data;
                 if (chn.control & CTRL.MODE == CTRL.MODE_TIMER) {
                     if (chn.control & CTRL.TRIGGER == CTRL.TRIGGER_WAIT) {
@@ -208,19 +208,21 @@ pub fn Z80CTC(comptime P: Pins, comptime Bus: anytype) type {
                 // are then computed from the base vector plus 2 bytes per channel
                 if (0 == chn_id) {
                     for (0..NUM_CHANNELS) |i| {
-                        self.chn[i].int_vector = (data & 0xF8) + 2 * i;
+                        self.chn[i].int_vector = @truncate((data & 0xF8) + 2 * i);
                     }
                 }
             }
             return bus;
         }
 
-        fn _tick(bus: Bus) Bus {
+        fn _tick(self: *Self, bus: Bus) Bus {
+            _ = self; // autofix
             // FIXME
             return bus;
         }
 
-        fn irq(bus: Bus) Bus {
+        fn irq(self: *Self, bus: Bus) Bus {
+            _ = self; // autofix
             // FIXME:
             return bus;
         }
@@ -246,6 +248,7 @@ pub fn Z80CTC(comptime P: Pins, comptime Bus: anytype) type {
                 chn.waiting_for_trigger = false;
                 chn.down_counter = chn.constant;
             }
+            return bus;
         }
 
         // called when the downcounter reaches zero, request interrupt,
@@ -254,13 +257,13 @@ pub fn Z80CTC(comptime P: Pins, comptime Bus: anytype) type {
         fn counterZero(chn: *Channel, in_bus: Bus, chn_id: usize) Bus {
             var bus = in_bus;
             // down counter has reached zero, trigger interrupt and ZCTO pin
-            if (chn.ctrl & CTRL.EI != 0) {
+            if (chn.control & CTRL.EI != 0) {
                 chn.irq_state |= IRQ.INT_NEEDED;
             }
             // last channel doesn't have a ZCTO pin
             if (chn_id < 3) {
                 // set the zcto pin
-                bus |= ZCTO0 << chn_id;
+                bus |= ZCTO0 << @truncate(chn_id);
             }
             // reload the down counter
             chn.down_counter = chn.constant;

diff --git a/tests/z80ctc.test.zig b/tests/z80ctc.test.zig
@@ -5,10 +5,55 @@ const Pins = z80ctc.DefaultPins;
 const Bus = u32;
 const Z80CTC = z80ctc.Z80CTC(Pins, Bus);
 
+const setData = Z80CTC.setData;
+const CE = Z80CTC.CE;
+const IORQ = Z80CTC.IORQ;
+const CS0 = Z80CTC.CS0;
+const CS1 = Z80CTC.CS1;
+const ZCTO1 = Z80CTC.ZCTO1;
+
+const CTRL = Z80CTC.CTRL;
+
 test "init Z80CTC" {
     const ctc = Z80CTC.init();
     for (0..3) |i| {
         try expect(ctc.chn[i].control & Z80CTC.CTRL.RESET != 0);
         try expect(ctc.chn[i].prescaler_mask == 0x0F);
     }
 }
+
+test "write int vector" {
+    var ctc = Z80CTC.init();
+    var bus = setData(CE | IORQ, 0xE0);
+    bus = ctc.tick(bus);
+    try expect(bus == setData(CE | IORQ, 0xE0));
+    try expect(ctc.chn[0].int_vector == 0xE0);
+    try expect(ctc.chn[1].int_vector == 0xE2);
+    try expect(ctc.chn[2].int_vector == 0xE4);
+    try expect(ctc.chn[3].int_vector == 0xE6);
+}
+
+test "timer" {
+    var ctc = Z80CTC.init();
+    const ctrl = CTRL.EI | CTRL.MODE_TIMER | CTRL.PRESCALER_16 | CTRL.TRIGGER_AUTO | CTRL.CONST_FOLLOWS | CTRL.CONTROL;
+    // write control word
+    var bus = ctc.tick(setData(CE | IORQ | CS0, ctrl));
+    try expect(ctc.chn[1].control == ctrl);
+    try expect(ctc.chn[1].prescaler_mask == 0x0F);
+    // write timer constant
+    bus = ctc.tick(setData(CE | IORQ | CS0, 10));
+    try expect(0 == ctc.chn[1].control & CTRL.CONST_FOLLOWS);
+    try expect(10 == ctc.chn[1].constant);
+    try expect(10 == ctc.chn[1].down_counter);
+    bus = 0;
+    for (0..3) |_| {
+        for (0..160) |tick| {
+            bus = ctc.tick(bus);
+            if (tick != 159) {
+                try expect(0 == bus & ZCTO1);
+            }
+        }
+        try expect(0 != bus & ZCTO1);
+        try expect(10 == ctc.chn[1].down_counter);
+    }
+}