--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cdd_mcu.h	Thu Jan 27 00:33:41 2022 -0800
@@ -0,0 +1,164 @@
+#ifndef CDD_MCU_H_
+#define CDD_MCU_H_
+#include "system.h"
+
+
+typedef enum {
+	SF_ABSOLUTE,
+	SF_RELATIVE,
+	SF_TRACK,
+	SF_TOCO,
+	SF_TOCT,
+	SF_TOCN,
+	SF_E,
+	SF_NOTREADY = 0xF
+} status_format;
+
+typedef enum {
+	CMD_NOP,
+	CMD_STOP,
+	CMD_REPORT_REQUEST,
+	CMD_READ,
+	CMD_SEEK,
+	CMD_INVALID,
+	CMD_PAUSE,
+	CMD_PLAY,
+	CMD_FFWD,
+	CMD_RWD,
+	CMD_TRACK_SKIP,
+	CMD_TRACK_CUE,
+	CMD_DOOR_CLOSE,
+	CMD_DOOR_OPEN
+} host_cmd;
+
+typedef enum {
+	DS_STOP,
+	DS_PLAY,
+	DS_SEEK,
+	DS_SCAN,
+	DS_PAUSE,
+	DS_DOOR_OPEN,
+	DS_SUM_ERROR,
+	DS_CMD_ERROR,
+	DS_FUNC_ERROR,
+	DS_TOC_READ,
+	DS_TRACKING,
+	DS_NO_DISC,
+	DS_DISC_LEADOUT,
+	DS_DISC_LEADIN,
+	DS_TRAY_MOVING,
+} drive_status;
+
+
+typedef struct {
+	uint8_t status;
+	uint8_t format;
+	union {
+		struct {
+			uint8_t min_high;
+			uint8_t min_low;
+			uint8_t sec_high;
+			uint8_t sec_low;
+			uint8_t frame_high;
+			uint8_t frame_low;
+			uint8_t flags;
+		} time;
+		struct {
+			uint8_t track_high;
+			uint8_t track_low;
+			uint8_t padding0;
+			uint8_t padding1;
+			uint8_t control;
+			uint8_t padding2;
+			uint8_t flags;
+		} track;
+		struct {
+			uint8_t first_track_high;
+			uint8_t first_track_low;
+			uint8_t last_track_high;
+			uint8_t last_track_low;
+			uint8_t version;
+			uint8_t padding;
+			uint8_t flags;
+		} toct;
+		struct {
+			uint8_t min_high;
+			uint8_t min_low;
+			uint8_t sec_high;
+			uint8_t sec_low;
+			uint8_t frame_high;
+			uint8_t frame_low;
+			uint8_t track_low;
+		} tocn;
+		struct {
+		} error;
+	} b;
+	uint8_t checksum;
+} cdd_status;
+
+typedef struct {
+	uint8_t cmd_type;
+	uint8_t must_be_zero;
+	union {
+		struct {
+			uint8_t min_high;
+			uint8_t min_low;
+			uint8_t sec_high;
+			uint8_t sec_low;
+			uint8_t frame_high;
+			uint8_t frame_low;
+		} time;
+		struct {
+			uint8_t padding;
+			uint8_t status_type;
+			uint8_t track_high;
+			uint8_t track_low;
+		} format;
+		struct {
+			uint8_t padding;
+			uint8_t direction;
+			uint8_t tracks_highest;
+			uint8_t tracks_midhigh;
+			uint8_t tracks_midlow;
+			uint8_t tracks_lowest;
+		} skip;
+		struct {
+			uint8_t track_high;
+			uint8_t track_low;
+		} track;
+	} b;
+	uint8_t padding;
+	uint8_t checksum;
+} cdd_cmd;
+
+typedef struct {
+	system_media  *media;
+	uint32_t      cycle;          //this is in CD block CLKS
+	uint32_t      next_int_cycle; //this is in SCD MCLKS
+	uint32_t      last_subcode_cycle;
+	uint32_t      last_nibble_cycle;
+	int           current_status_nibble;
+	int           current_cmd_nibble;
+	uint32_t      head_pba;
+	uint32_t      seek_pba;
+	cdd_status    status_buffer;
+	cdd_cmd       cmd_buffer;
+	status_format requested_format;
+	drive_status  status;
+	drive_status  error_status;
+	uint8_t       requested_track;
+	uint8_t       cmd_recv_wait;
+	uint8_t       cmd_recv_pending;
+	uint8_t       int_pending;
+	uint8_t       toc_valid;
+	uint8_t       seeking;
+} cdd_mcu;
+
+void cdd_mcu_init(cdd_mcu *context, system_media *media);
+void cdd_mcu_run(cdd_mcu *context, uint32_t cycle, uint16_t *gate_array);
+void cdd_hock_enabled(cdd_mcu *context);
+void cdd_hock_disabled(cdd_mcu *context);
+void cdd_mcu_start_cmd_recv(cdd_mcu *context, uint16_t *gate_array);
+void cdd_mcu_adjust_cycle(cdd_mcu *context, uint32_t deduction);
+
+#endif //CD_MCU_H_