Begin implementing DMA: impl memory to VRAM

1 files changed, 11 insertions, 3 deletions

diff --git a/vdp.hpp b/vdp.hpp
index 9357377..030b38e 100644
--- a/vdp.hpp
+++ b/vdp.hpp
@@ -57,8 +57,8 @@ class VDP {
             kScrollSize = 16,
             kWindowHorizontalPosition = 17,
             kWindowVertialPosition = 18,
-            kDMACounterLow = 19,
-            kDMACounterHigh = 20,
+            kDMALengthCounterLow = 19,
+            kDMALengthCounterHigh = 20,
             kDMASourceAddressLow = 21,
             kDMASourceAddressMid = 22,
             kDMASourceAddressHigh = 23,
@@ -69,10 +69,18 @@ class VDP {
         void writeControl(uint16_t value);
         uint16_t readData(uint8_t address_mode, uint16_t address);
         uint16_t readStatusRegister() const;
-
+        uint8_t* baseFromAddressMode(uint8_t address_mode);
         const char* addressModeToString(uint8_t address_mode);
         const char* regIDToString(RegID);
 
+        static void runDMAMemoryToVRAM(
+                uint8_t* base,
+                uint32_t source_address,
+                uint16_t destination_address,
+                uint16_t transfer_size);
+        static void runDMAVRAMFill(uint8_t* base);
+        static void runDMAVRAMCopy(uint8_t* base);
+
         static constexpr size_t kRegistersCount = static_cast<size_t>(RegID::kRegistersCount);
         static constexpr size_t kVRAMSize = 64*1024;
         static constexpr size_t kCRAMSize = 64*2;