Implement communication port

core/vb.c

@@ -146,6 +146,28 @@ struct VB {
         int      step;      /* Operation sub-task ID */
     } cpu;
 
+    /* Communication port */
+    struct {
+
+        /* Register state */
+        uint8_t c_clk_sel;  /* Transmission clock source */
+        uint8_t c_int_inh;  /* Interrupt acknowledge/disable */
+        uint8_t c_stat;     /* Communication is underway */
+        uint8_t cc_int_inh; /* Interrupt acknowledge/disable */
+        uint8_t cc_int_lev; /* Interrupt condition */
+        uint8_t cc_rd;      /* Manual read */
+        uint8_t cc_sig;     /* Automatic write */
+        uint8_t cc_smp;     /* Automatic read */
+        uint8_t cc_wr;      /* Manual write */
+        uint8_t cdrr;       /* Data received */
+        uint8_t cdtr;       /* Data to transmit */
+
+        /* Other state */
+        int8_t   c_irq;  /* COM interrupt request */
+        int8_t   cc_irq; /* COMCNT interrupt request */
+        uint32_t clocks; /* Master clocks to wait */
+    } ext;
+
     /* Game pad */
     struct {
 
@@ -159,8 +181,9 @@ struct VB {
         uint8_t  soft_ck;   /* Controller communication signal */
 
         /* Other state */
-        uint16_t keys; /* Next input bits */
-        int      step; /* Software read processing phase */
+        uint32_t clocks; /* Master clocks to wait */
+        uint16_t keys;   /* Next input bits */
+        int      step;   /* Software read processing phase */
     } pad;
 
     /* Timer */
@@ -310,6 +333,12 @@ struct VB {
         int      sample; /* Output sample index, period 417 */
     } vsu;
 
+    /* Wait controller */
+    struct {
+        uint8_t exp1w; /* Cartridge expansion 1-wait */
+        uint8_t rom1w; /* Cartridge ROM 1-wait */
+    } wcr;
+
     /* Pseudo-halt */
     struct {
         uint32_t address;   /* Monitor address */
@@ -335,7 +364,6 @@ struct VB {
     } ph;
 
     /* Other state */
-    uint8_t wcr;           /* Wait controller state */
     uint8_t wram[0x10000]; /* System RAM */
 
     /* Application data */
@@ -343,9 +371,11 @@ struct VB {
     vbOnExecute   onExecute;   /* CPU instruction execute */
     vbOnFetch     onFetch;     /* CPU instruction fetch */
     vbOnFrame     onFrame;     /* VIP frame ready */
+    vbOnLink      onLink;      /* Communication transfer */
     vbOnRead      onRead;      /* CPU instruction read */
     vbOnSamples   onSamples;   /* VSU samples full */
     vbOnWrite     onWrite;     /* CPU instruction write */
+    VB           *peer;        /* Communication peer */
     void         *tag;         /* User data */
 };
 
@@ -368,6 +398,7 @@ static int32_t SignExtend(int32_t value, int32_t bits) {
 
 /******************************** Sub-Modules ********************************/
 
+#include "ext.c"
 #include "game-pad.c"
 #include "timer.c"
 #include "bus.c"
@@ -391,7 +422,8 @@ static int sysEmulate(VB *sim, uint32_t clocks) {
     ;
 
     /* Process all components */
-    if (!never) ret  = cpuEmulate(sim, clocks);
+    if (!never){ret  = cpuEmulate(sim, clocks);}
+                ret |= extEmulate(sim, clocks);
                        padEmulate(sim, clocks);
                        tmrEmulate(sim, clocks);
                        vsuEmulate(sim, clocks);
@@ -403,6 +435,7 @@ static int sysEmulate(VB *sim, uint32_t clocks) {
 /* Determine how many clocks are guaranteed to process */
 static uint32_t sysUntil(VB *sim, uint32_t clocks) {
     clocks = cpuUntil(sim, clocks);
+    clocks = extUntil(sim, clocks);
     clocks = padUntil(sim, clocks);
     clocks = tmrUntil(sim, clocks);
     clocks = vipUntil(sim, clocks);
@@ -487,6 +520,11 @@ VBAPI uint16_t vbGetKeys(VB *sim) {
     return sim->pad.keys;
 }
 
+/* Retrieve the current link callback handler */
+VBAPI vbOnLink vbGetLinkCallback(VB *sim) {
+    return sim->onLink;
+}
+
 /* Retrieve a core option value */
 VBAPI int vbGetOption(VB *sim, int key) {
     switch (key) {
@@ -495,6 +533,11 @@ VBAPI int vbGetOption(VB *sim, int key) {
     return 0;
 }
 
+/* Retrieve the communication peer */
+VBAPI VB* vbGetPeer(VB *sim) {
+    return sim->peer;
+}
+
 /* Retrieve the most recent frame image pixels */
 VBAPI void vbGetPixels(VB *sim, void *left, int leftStrideX, int leftStrideY,
     void *right, int rightStrideX, int rightStrideY) {
@@ -594,9 +637,11 @@ VBAPI VB* vbInit(VB *sim) {
     sim->onExecute       = NULL;
     sim->onFetch         = NULL;
     sim->onFrame         = NULL;
+    sim->onLink          = NULL;
     sim->onRead          = NULL;
     sim->onSamples       = NULL;
     sim->onWrite         = NULL;
+    sim->peer            = NULL;
     sim->ph.enabled      = 0;
     vbReset(sim);
     return sim;
@@ -616,7 +661,8 @@ VBAPI VB* vbReset(VB *sim) {
     int x; /* Iterator */
 
     /* Wait controller */
-    sim->wcr = 0x00;
+    sim->wcr.exp1w = 0;
+    sim->wcr.rom1w = 0;
 
     /* WRAM (the hardware does not do this) */
     for (x = 0; x < 0x10000; x++)
@@ -624,6 +670,7 @@ VBAPI VB* vbReset(VB *sim) {
 
     /* Components */
     cpuReset(sim);
+    extReset(sim);
     padReset(sim);
     tmrReset(sim);
     vipReset(sim);
@@ -689,6 +736,13 @@ VBAPI uint16_t vbSetKeys(VB *sim, uint16_t keys) {
     return sim->pad.keys = keys;
 }
 
+/* Specify a new link callback handler */
+VBAPI vbOnLink vbSetLinkCallback(VB *sim, vbOnLink callback) {
+    vbOnLink prev = sim->onLink;
+    sim->onLink = callback;
+    return prev;
+}
+
 /* Specify a new core option value */
 VBAPI int vbSetOption(VB *sim, int key, int value) {
     switch (key) {
@@ -706,6 +760,15 @@ VBAPI int vbSetOption(VB *sim, int key, int value) {
     return value;
 }
 
+/* Specify a new communication peer */
+VBAPI VB* vbSetPeer(VB *sim, VB *peer) {
+    VB *prev  = sim->peer;
+    sim->peer = peer;
+    if (peer != prev && prev != NULL)
+        prev->peer = NULL;
+    return prev;
+}
+
 /* Specify a new value for the program counter */
 VBAPI uint32_t vbSetProgramCounter(VB *sim, uint32_t value) {
     sim->cpu.operation = CPU_FETCH;