[sh4] Init timers

Senryoku · Jul 14, 2024 · c466254 · c466254
1 parent d4a8272
commit c466254
Showing 1 changed file with 18 additions and 9 deletions.
diff --git a/src/sh4.zig b/src/sh4.zig
@@ -73,6 +73,12 @@ pub const FPSCR = packed struct(u32) {
     _: u10 = undefined, // Reserved
 };
 
+const TimerRegisters = [3]struct { counter: P4Register, control: P4Register, constant: P4Register, interrupt: Interrupt }{
+    .{ .counter = P4Register.TCNT0, .control = P4Register.TCR0, .constant = P4Register.TCOR0, .interrupt = Interrupt.TUNI0 },
+    .{ .counter = P4Register.TCNT1, .control = P4Register.TCR1, .constant = P4Register.TCOR1, .interrupt = Interrupt.TUNI1 },
+    .{ .counter = P4Register.TCNT2, .control = P4Register.TCR2, .constant = P4Register.TCOR2, .interrupt = Interrupt.TUNI2 },
+};
+
 pub const VirtualAddr = packed struct {
     region: u3,
     addr: u29,
@@ -265,6 +271,14 @@ pub const SH4 = struct {
         self.p4_register(u16, .IPRC).* = 0x0000;
         self.compute_interrupt_priorities();
 
+        self.p4_register(u8, .TOCR).* = 0x00;
+        self.p4_register(u8, .TSTR).* = 0x00;
+        for (TimerRegisters) |timer| {
+            self.p4_register(u32, timer.constant).* = 0xFFFFFFFF;
+            self.p4_register(u32, timer.counter).* = 0xFFFFFFFF;
+            self.p4_register(u16, timer.control).* = 0x0000;
+        }
+
         self.p4_register(u8, .SCBRR2).* = 0xFF;
         self.p4_register(u16, .SCSCR2).* = 0x0000;
         self.p4_register(u16, .SCFSR2).* = 0x0060;
@@ -646,16 +660,11 @@ pub const SH4 = struct {
         // set in the corresponding timer control register (TCR). If the UNIE bit in TCR is set to 1 at this
         // time, an interrupt request is sent to the CPU. At the same time, the value is copied from TCOR
         // into TCNT, and the count-down continues (auto-reload function).
-        const timers = .{
-            .{ .counter = P4Register.TCNT0, .control = P4Register.TCR0, .constant = P4Register.TCOR0, .interrupt = Interrupt.TUNI0 },
-            .{ .counter = P4Register.TCNT1, .control = P4Register.TCR1, .constant = P4Register.TCOR1, .interrupt = Interrupt.TUNI1 },
-            .{ .counter = P4Register.TCNT2, .control = P4Register.TCR2, .constant = P4Register.TCOR2, .interrupt = Interrupt.TUNI2 },
-        };
 
         inline for (0..3) |i| {
             if ((TSTR >> @intCast(i)) & 0x1 == 1) {
-                const tcnt = self.p4_register(u32, timers[i].counter);
-                const tcr = self.p4_register(P4.TCR, timers[i].control);
+                const tcnt = self.p4_register(u32, TimerRegisters[i].counter);
+                const tcr = self.p4_register(P4.TCR, TimerRegisters[i].control);
 
                 self.timer_cycle_counter[i] += cycles;
 
@@ -666,9 +675,9 @@ pub const SH4 = struct {
 
                     if (tcnt.* == 0) {
                         tcr.*.unf = 1; // Signals underflow
-                        tcnt.* = self.p4_register(u32, timers[i].constant).*; // Reset counter
+                        tcnt.* = self.p4_register(u32, TimerRegisters[i].constant).*; // Reset counter
                         if (tcr.*.unie == 1)
-                            self.request_interrupt(timers[i].interrupt);
+                            self.request_interrupt(TimerRegisters[i].interrupt);
                     } else {
                         tcnt.* -= 1;
                     }