start with z80pio tests

src/chips/z80pio.zig

@@ -2,7 +2,7 @@
 const bitutils = @import("common").bitutils;
 const mask = bitutils.mask;
 const maskm = bitutils.maskm;
-const Z80IRQ = @import("z80irq").Z80IRQ;
+const Z80IRQ = @import("z80irq.zig").Z80IRQ;
 
 /// Z80 PIO pin declarations
 pub const Pins = struct {
@@ -197,7 +197,7 @@ pub fn Z80PIO(comptime P: Pins, comptime Bus: anytype) type {
         }
 
         pub fn reset(self: *Self) void {
-            self.reset_active = false;
+            self.reset_active = true;
             for (&self.ports) |*port| {
                 port.mode = MODE.INPUT;
                 port.output = 0;

tests/build.zig

@@ -39,6 +39,7 @@ pub fn build(b: *Build, opts: Options) void {
         "memory",
         "ay3891",
         "z80ctc",
+        "z80pio",
     };
     const test_step = b.step("test", "Run unit tests");
     inline for (unit_tests) |name| {

tests/z80pio.test.zig

@@ -0,0 +1,21 @@
+const std = @import("std");
+const expect = std.testing.expect;
+const chipz = @import("chipz");
+const z80pio = chipz.chips.z80pio;
+
+const Bus = u64;
+const Z80PIO = z80pio.Z80PIO(z80pio.DefaultPins, Bus);
+
+const MODE = Z80PIO.MODE;
+const INTCTRL = Z80PIO.INTCTRL;
+
+test "init Z80PIO" {
+    const pio = Z80PIO.init();
+    try expect(pio.reset_active);
+    for (&pio.ports) |*p| {
+        try expect(p.mode == MODE.INPUT);
+        try expect(p.int_mask == 0xFF);
+    }
+}
+
+// FIXME: more tests