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picodrive/pico/videoport.c
kub 17bd69adc6 revised VDP fifo implementation
2020-02-07 22:14:34 +01:00

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/*
* PicoDrive
* (c) Copyright Dave, 2004
* (C) notaz, 2006-2009
*
* This work is licensed under the terms of MAME license.
* See COPYING file in the top-level directory.
*/
#include "pico_int.h"
#define NEED_DMA_SOURCE
#include "memory.h"
extern const unsigned char hcounts_32[];
extern const unsigned char hcounts_40[];
static unsigned hvlatch; // latched hvcounter value
static int blankline; // display disabled for this line
int (*PicoDmaHook)(unsigned int source, int len, unsigned short **base, unsigned int *mask) = NULL;
/* VDP FIFO implementation
*
* fifo_slot: last slot executed in this scanline
* fifo_cnt: #slots remaining for active FIFO write (#writes<<#bytep)
* fifo_total: #total FIFO entries pending
* fifo_data: last values transferred through fifo
* fifo_queue: fifo transfer queue (#writes, VRAM_byte_p)
*
* FIFO states: empty total=0
* inuse total>0 && total<4
* full total==4
* wait total>4
* Conditions:
* fifo_slot is always behind slot2cyc[cycles]. Advancing it beyond cycles
* implies blocking the 68k up to that slot.
*
* A FIFO write goes to the end of the fifo queue. There can be more pending
* writes than FIFO slots, but the 68k will be blocked in most of those cases.
* This is only about correct timing, data xfer must be handled by the caller.
* Blocking the CPU means burning cycles via SekCyclesBurn*(), which is to be
* executed by the caller.
*
* FIFOSync "executes" FIFO write slots up to the given cycle in the current
* scanline. A queue entry completely executed is removed from the queue.
* FIFOWrite pushes writes to the transfer queue. If it's a blocking write, 68k
* is blocked if more than 4 FIFO writes are pending.
* FIFORead executes a 68k read. 68k is blocked until the next transfer slot.
*/
// FIFO transfer slots per line: H32 blank, H40 blank, H32 active, H40 active
static const short vdpslots[] = { 166, 204, 16, 18 };
// mapping between slot# and 68k cycles in a blanked scanline
static const int vdpcyc2sl_bl[] = { (166<<16)/488, (204<<16)/488, (16<<16)/488, (18<<16)/488 };
static const int vdpsl2cyc_bl[] = { (488<<16)/166, (488<<16)/204, (488<<16)/16, (488<<16)/18 };
// VDP transfer slots in active display 32col mode. 1 slot is 488/171 = 2.8538
// 68k cycles. Only 16 of the 171 slots in a scanline can be used by CPU/DMA:
// (HINT=slot 0): 13,27,42,50,58,74,82,90,106,114,122,138,146,154,169,170
const unsigned char vdpcyc2sl_32[] = { // 68k cycles/4 since HINT to slot #
// 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3,
3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9,
9,10,10,10,10,10,10,11,11,11,11,11,11,11,11,11,
11,11,12,12,12,12,12,12,13,13,13,13,13,13,14,14,
14,14,14,14,14,14,14,14,15,16,16,16,16,16,16,16,
};
const unsigned char vdpsl2cyc_32[] = { // slot # to 68k cycles/4 since HINT
0, 9, 19, 30, 35, 41, 52, 58, 64, 75, 81, 87, 98,104,110,120,121,123,123
};
// VDP transfer slots in active display 40col mode. 1 slot is 488/210 = 2.3238
// 68k cycles. Only 18 of the 210 slots in a scanline can be used by CPU/DMA:
// (HINT=0): 23,49,57,65,81,89,97,113,121,129,145,153,161,177,185,193,208,209
const unsigned char vdpcyc2sl_40[] = { // 68k cycles/4 since HINT to slot #
// 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2,
2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5,
5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7,
7, 8, 8, 8, 8, 8, 9, 9, 9, 9,10,10,10,10,10,10,
10,10,10,10,11,11,11,11,12,12,12,12,12,13,13,13,
13,13,13,13,13,13,14,14,14,14,14,15,15,15,15,15,
16,16,16,16,16,16,16,16,17,18,18,18,18,18,18,18,
};
const unsigned char vdpsl2cyc_40[] = { // slot # to 68k cycles/4 since HINT
0, 13, 28, 33, 37, 47, 51, 56, 65, 70, 74, 84, 88, 93,102,107,112,120,121,123,123
};
// NB code assumes fifo_* arrays have size 2^n
// last transferred FIFO data, ...x = index XXX currently only CPU
static short fifo_data[4], fifo_dx;
// queued FIFO transfers, ...x = index, ...l = queue length
// each entry has 2 values: [n]>>1=#writes, [n]&1=is VRAM byte access
static int fifo_queue[8], fifo_qx, fifo_ql;
signed int fifo_cnt; // pending slots for current queue entry
unsigned short fifo_slot; // last executed slot in current scanline
unsigned int fifo_total; // total# of pending FIFO entries
// sync FIFO to cycles
void PicoVideoFIFOSync(int cycles)
{
struct PicoVideo *pv = &Pico.video;
int active = !(pv->status & SR_VB) && (pv->reg[1] & 0x40);
int h40 = pv->reg[12] & 1;
const unsigned char *cs = h40 ? vdpcyc2sl_40 : vdpcyc2sl_32;
int slots, done;
// calculate #slots since last executed slot
if (active) slots = cs[cycles/4];
else slots = (cycles * vdpcyc2sl_bl[h40] + cycles) >> 16;
slots -= fifo_slot;
// advance FIFO queue by #done slots
done = slots;
while (done > 0 && fifo_ql) {
int l = done, b = fifo_queue[fifo_qx&7] & 1;
if (l > fifo_cnt)
l = fifo_cnt;
fifo_total -= ((fifo_cnt & b) + l) >> b;
fifo_slot += l;
fifo_cnt -= l;
done -= l;
if (fifo_cnt == 0) {
fifo_qx ++, fifo_ql --;
fifo_cnt= (fifo_queue[fifo_qx&7] >> 1) << (fifo_queue[fifo_qx&7] & 1);
}
}
// release CPU and terminate DMA if FIFO isn't blocking the 68k anymore
if (fifo_total <= 4) {
pv->status &= ~PVS_CPUWR;
pv->command &= ~0x80;
if (!(pv->status & PVS_DMAPEND))
pv->status &= ~(SR_DMA|PVS_DMAFILL);
}
if (fifo_total == 0)
pv->status &= ~PVS_CPURD;
}
// drain FIFO, blocking 68k on the way. FIFO must be synced prior to drain.
int PicoVideoFIFODrain(int level, int cycles)
{
struct PicoVideo *pv = &Pico.video;
int active = !(pv->status & SR_VB) && (pv->reg[1] & 0x40);
int h40 = pv->reg[12] & 1;
const unsigned char *sc = h40 ? vdpsl2cyc_40 : vdpsl2cyc_32;
int maxsl = vdpslots[h40 + 2*active]; // max xfer slots in this scanline
int burn = 0;
while (fifo_total > level && fifo_slot < maxsl) {
int b = fifo_queue[fifo_qx&7] & 1;
int cnt = (fifo_total-level) << b;
int last = fifo_slot;
int slot = (fifo_cnt<cnt?fifo_cnt:cnt) + last; // target slot
unsigned ocyc = cycles;
if (slot > maxsl) {
// target in later scanline, advance to eol
slot = maxsl;
fifo_slot = maxsl;
cycles = 488;
} else {
// advance FIFO to target slot and CPU to cycles at that slot
fifo_slot = slot;
if (active) cycles = sc[slot]*4;
else cycles = ((slot * vdpsl2cyc_bl[h40] + slot) >> 16);
}
burn += cycles - ocyc;
slot -= last;
fifo_total -= ((fifo_cnt & b) + slot) >> b;
fifo_cnt -= slot;
if (fifo_cnt == 0) {
fifo_qx ++, fifo_ql --;
fifo_cnt= (fifo_queue[fifo_qx&7] >> 1) << (fifo_queue[fifo_qx&7] & 1);
}
}
// release CPU and terminate DMA if FIFO isn't blocking the bus anymore
if (fifo_total <= 4) {
pv->status &= ~PVS_CPUWR;
pv->command &= ~0x80;
if (!(pv->status & PVS_DMAPEND))
pv->status &= ~(SR_DMA|PVS_DMAFILL);
}
if (fifo_total == 0)
pv->status &= ~PVS_CPURD;
return burn;
}
// read VDP data port
int PicoVideoFIFORead(void)
{
struct PicoVideo *pv = &Pico.video;
int active = !(pv->status & SR_VB) && (pv->reg[1] & 0x40);
int h40 = pv->reg[12] & 1;
const unsigned char *cs = h40 ? vdpcyc2sl_40 : vdpcyc2sl_32;
const unsigned char *sc = h40 ? vdpsl2cyc_40 : vdpsl2cyc_32;
int lc = SekCyclesDone()-Pico.t.m68c_line_start+4;
int burn = 0;
PicoVideoFIFOSync(lc);
// advance FIFO and CPU until FIFO is empty
burn = PicoVideoFIFODrain(0, lc);
lc += burn;
if (fifo_total > 0)
pv->status |= PVS_CPURD; // target slot is in later scanline
else {
// use next VDP access slot for reading, block 68k until then
if (active) {
fifo_slot = cs[lc/4] + 1;
burn += sc[fifo_slot]*4;
} else {
fifo_slot = ((lc * vdpcyc2sl_bl[h40] + lc) >> 16) + 1;
burn += ((fifo_slot * vdpsl2cyc_bl[h40] + fifo_slot) >> 16);
}
burn -= lc;
}
return burn;
}
// write VDP data port
int PicoVideoFIFOWrite(int count, int byte_p, unsigned sr_mask,unsigned sr_flags)
{
struct PicoVideo *pv = &Pico.video;
int active = !(pv->status & SR_VB) && (pv->reg[1] & 0x40);
int h40 = pv->reg[12] & 1;
const unsigned char *cs = h40 ? vdpcyc2sl_40 : vdpcyc2sl_32;
int lc = SekCyclesDone()-Pico.t.m68c_line_start+4;
int burn = 0;
PicoVideoFIFOSync(lc);
pv->status = (pv->status & ~sr_mask) | sr_flags;
if (count) {
// update FIFO state if it was empty
if (fifo_total == 0 && count) {
if (active) fifo_slot = cs[lc/4];
else fifo_slot = (lc * vdpcyc2sl_bl[h40] + lc) >> 16;
fifo_cnt = count << byte_p;
}
// create xfer queue entry
int x = (fifo_qx + fifo_ql) & 7;
fifo_queue[x] = (count << 1) | byte_p;
fifo_ql ++;
fifo_total += count;
}
// if CPU is waiting for the bus, advance CPU and FIFO until bus is free
if ((pv->status & (PVS_CPUWR|PVS_DMAFILL)) == PVS_CPUWR)
burn = PicoVideoFIFODrain(4, lc);
return burn;
}
// at HINT, advance FIFO to new scanline
int PicoVideoFIFOHint(void)
{
struct PicoVideo *pv = &Pico.video;
int burn = 0;
// reset slot to start of scanline
fifo_slot = 0;
// if CPU is waiting for the bus, advance CPU and FIFO until bus is free
if (pv->status & PVS_CPURD)
burn = PicoVideoFIFORead();
if (pv->status & PVS_CPUWR)
burn = PicoVideoFIFOWrite(0, 0, 0, 0);
return burn;
}
// switch FIFO mode between active/inactive display
void PicoVideoFIFOMode(int active)
{
struct PicoVideo *pv = &Pico.video;
const unsigned char *cs = pv->reg[12]&1 ? vdpcyc2sl_40 : vdpcyc2sl_32;
int h40 = pv->reg[12] & 1;
int lc = SekCyclesDone() - Pico.t.m68c_line_start;
PicoVideoFIFOSync(lc);
if (fifo_total) {
// recalculate FIFO slot for new mode
if (!(pv->status & SR_VB) && active)
fifo_slot = cs[lc/4];
else fifo_slot = ((lc * vdpcyc2sl_bl[h40] + lc) >> 16);
}
}
// VDP memory rd/wr
static __inline void AutoIncrement(void)
{
Pico.video.addr=(unsigned short)(Pico.video.addr+Pico.video.reg[0xf]);
}
static NOINLINE unsigned int VideoWrite128(u32 a, u16 d)
{
// nasty
a = ((a & 2) >> 1) | ((a & 0x400) >> 9) | (a & 0x3FC) | ((a & 0x1F800) >> 1);
((u8 *)PicoMem.vram)[a] = d;
return a;
}
static void VideoWrite(u16 d)
{
unsigned int a = Pico.video.addr;
switch (Pico.video.type)
{
case 1: if (a & 1)
d = (u16)((d << 8) | (d >> 8));
PicoMem.vram [(a >> 1) & 0x7fff] = d;
if ((unsigned)(a - ((Pico.video.reg[5]&0x7f) << 9)) < 0x400)
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
break;
case 3: if (PicoMem.cram [(a >> 1) & 0x3f] != d) Pico.m.dirtyPal = 1;
PicoMem.cram [(a >> 1) & 0x3f] = d; break;
case 5: PicoMem.vsram[(a >> 1) & 0x3f] = d; break;
case 0x81: if (a & 1)
d = (u16)((d << 8) | (d >> 8));
a |= Pico.video.addr_u << 16;
a = VideoWrite128(a, d);
if ((unsigned)(a - ((Pico.video.reg[5]&0x7f) << 9)) < 0x400)
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
break;
//default:elprintf(EL_ANOMALY, "VDP write %04x with bad type %i", d, Pico.video.type); break;
}
AutoIncrement();
}
static unsigned int VideoRead(void)
{
unsigned int a, d = fifo_data[(fifo_dx+1)&3];
a=Pico.video.addr; a>>=1;
SekCyclesBurnRun(PicoVideoFIFORead());
switch (Pico.video.type)
{
case 0: d=PicoMem.vram [a & 0x7fff]; break;
case 8: d=(PicoMem.cram [a & 0x003f] & 0x0eee) | (d & ~0x0eee); break;
case 4: if ((a & 0x3f) >= 0x28) a = 0;
d=(PicoMem.vsram [a & 0x003f] & 0x07ff) | (d & ~0x07ff); break;
case 12:a=PicoMem.vram [a & 0x7fff]; if (Pico.video.addr&1) a >>= 8;
d=(a & 0x00ff) | (d & ~0x00ff); break;
default:elprintf(EL_ANOMALY, "VDP read with bad type %i", Pico.video.type); break;
}
AutoIncrement();
return d;
}
// VDP DMA
static int GetDmaLength(void)
{
struct PicoVideo *pvid=&Pico.video;
int len=0;
// 16-bit words to transfer:
len =pvid->reg[0x13];
len|=pvid->reg[0x14]<<8;
len = ((len - 1) & 0xffff) + 1;
return len;
}
static void DmaSlow(int len, unsigned int source)
{
u32 inc = Pico.video.reg[0xf];
u32 a = Pico.video.addr;
u16 *r, *base = NULL;
u32 mask = 0x1ffff;
elprintf(EL_VDPDMA, "DmaSlow[%i] %06x->%04x len %i inc=%i blank %i [%u] @ %06x",
Pico.video.type, source, a, len, inc, (Pico.video.status&SR_VB)||!(Pico.video.reg[1]&0x40),
SekCyclesDone(), SekPc);
SekCyclesBurnRun(PicoVideoFIFOWrite(len, Pico.video.type == 1, PVS_DMAPEND,
SR_DMA | PVS_CPUWR) + 8);
if ((source & 0xe00000) == 0xe00000) { // Ram
base = (u16 *)PicoMem.ram;
mask = 0xffff;
}
else if (PicoIn.AHW & PAHW_MCD)
{
u8 r3 = Pico_mcd->s68k_regs[3];
elprintf(EL_VDPDMA, "DmaSlow CD, r3=%02x", r3);
if (source < 0x20000) { // Bios area
base = (u16 *)Pico_mcd->bios;
} else if ((source & 0xfc0000) == 0x200000) { // Word Ram
if (!(r3 & 4)) { // 2M mode
base = (u16 *)(Pico_mcd->word_ram2M + (source & 0x20000));
} else {
if (source < 0x220000) { // 1M mode
int bank = r3 & 1;
base = (u16 *)(Pico_mcd->word_ram1M[bank]);
} else {
DmaSlowCell(source - 2, a, len, inc);
return;
}
}
source -= 2;
} else if ((source & 0xfe0000) == 0x020000) { // Prg Ram
base = (u16 *)Pico_mcd->prg_ram_b[r3 >> 6];
source -= 2; // XXX: test
}
}
else
{
// if we have DmaHook, let it handle ROM because of possible DMA delay
u32 source2;
if (PicoDmaHook && (source2 = PicoDmaHook(source, len, &base, &mask)))
source = source2;
else // Rom
base = m68k_dma_source(source);
}
if (!base) {
elprintf(EL_VDPDMA|EL_ANOMALY, "DmaSlow[%i] %06x->%04x: invalid src", Pico.video.type, source, a);
return;
}
// operate in words
source >>= 1;
mask >>= 1;
switch (Pico.video.type)
{
case 1: // vram
r = PicoMem.vram;
if (inc == 2 && !(a & 1) && a + len * 2 < 0x10000
&& !(((source + len - 1) ^ source) & ~mask))
{
// most used DMA mode
memcpy((char *)r + a, base + (source & mask), len * 2);
a += len * 2;
}
else
{
for(; len; len--)
{
u16 d = base[source++ & mask];
if(a & 1) d=(d<<8)|(d>>8);
r[a >> 1] = d;
// AutoIncrement
a = (u16)(a + inc);
}
}
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
break;
case 3: // cram
Pico.m.dirtyPal = 1;
r = PicoMem.cram;
for (; len; len--)
{
r[(a / 2) & 0x3f] = base[source++ & mask];
// AutoIncrement
a += inc;
}
break;
case 5: // vsram
r = PicoMem.vsram;
for (; len; len--)
{
r[(a / 2) & 0x3f] = base[source++ & mask];
// AutoIncrement
a += inc;
}
break;
case 0x81: // vram 128k
a |= Pico.video.addr_u << 16;
for(; len; len--)
{
VideoWrite128(a, base[source++ & mask]);
// AutoIncrement
a = (a + inc) & 0x1ffff;
}
Pico.video.addr_u = a >> 16;
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
break;
default:
if (Pico.video.type != 0 || (EL_LOGMASK & EL_VDPDMA))
elprintf(EL_VDPDMA|EL_ANOMALY, "DMA with bad type %i", Pico.video.type);
break;
}
// remember addr
Pico.video.addr=(u16)a;
}
static void DmaCopy(int len)
{
u16 a = Pico.video.addr;
u8 *vr = (u8 *)PicoMem.vram;
u8 inc = Pico.video.reg[0xf];
int source;
elprintf(EL_VDPDMA, "DmaCopy len %i [%u]", len, SekCyclesDone());
SekCyclesBurnRun(PicoVideoFIFOWrite(len, 1, PVS_CPUWR|PVS_DMAPEND, SR_DMA));
source =Pico.video.reg[0x15];
source|=Pico.video.reg[0x16]<<8;
// XXX implement VRAM 128k? Is this even working?
for (; len; len--)
{
vr[a] = vr[source++ & 0xffff];
// AutoIncrement
a=(u16)(a+inc);
}
// remember addr
Pico.video.addr=a;
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
}
static NOINLINE void DmaFill(int data)
{
u16 a = Pico.video.addr;
u8 *vr = (u8 *)PicoMem.vram;
u8 high = (u8)(data >> 8);
u8 inc = Pico.video.reg[0xf];
int source;
int len, l;
len = GetDmaLength();
elprintf(EL_VDPDMA, "DmaFill len %i inc %i [%u]", len, inc, SekCyclesDone());
SekCyclesBurnRun(PicoVideoFIFOWrite(len, Pico.video.type == 1, PVS_CPUWR|PVS_DMAPEND, SR_DMA));
switch (Pico.video.type)
{
case 1: // vram
for (l = len; l; l--) {
// Write upper byte to adjacent address
// (here we are byteswapped, so address is already 'adjacent')
vr[a] = high;
// Increment address register
a = (u16)(a + inc);
}
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
break;
case 3: // cram
Pico.m.dirtyPal = 1;
for (l = len; l; l--) {
PicoMem.cram[(a/2) & 0x3f] = data;
// Increment address register
a += inc;
}
break;
case 5: { // vsram
for (l = len; l; l--) {
PicoMem.vsram[(a/2) & 0x3f] = data;
// Increment address register
a += inc;
}
break;
}
case 0x81: // vram 128k
for (l = len; l; l--) {
VideoWrite128(a, data);
// Increment address register
a = (a + inc) & 0x1ffff;
}
Pico.video.addr_u = a >> 16;
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
break;
default:
a += len * inc;
break;
}
// remember addr
Pico.video.addr = a;
// register update
Pico.video.reg[0x13] = Pico.video.reg[0x14] = 0;
source = Pico.video.reg[0x15];
source |= Pico.video.reg[0x16] << 8;
source += len;
Pico.video.reg[0x15] = source;
Pico.video.reg[0x16] = source >> 8;
}
// VDP command handling
static NOINLINE void CommandDma(void)
{
struct PicoVideo *pvid=&Pico.video;
u32 len, method;
u32 source;
pvid->status |= PVS_DMAPEND;
PicoVideoFIFOSync(SekCyclesDone()-Pico.t.m68c_line_start);
if (pvid->status & SR_DMA) {
elprintf(EL_VDPDMA, "Dma overlap, left=%d @ %06x",
fifo_total, SekPc);
fifo_total = fifo_ql = 0;
}
pvid->status |= SR_DMA;
len = GetDmaLength();
source =Pico.video.reg[0x15];
source|=Pico.video.reg[0x16] << 8;
source|=Pico.video.reg[0x17] << 16;
method=pvid->reg[0x17]>>6;
if (method < 2)
DmaSlow(len, source << 1); // 68000 to VDP
else if (method == 3)
DmaCopy(len); // VRAM Copy
else {
pvid->status |= PVS_DMAFILL;
return;
}
source += len;
Pico.video.reg[0x13] = Pico.video.reg[0x14] = 0;
Pico.video.reg[0x15] = source;
Pico.video.reg[0x16] = source >> 8;
}
static NOINLINE void CommandChange(void)
{
struct PicoVideo *pvid = &Pico.video;
unsigned int cmd, addr;
cmd = pvid->command;
// Get type of transfer 0xc0000030 (v/c/vsram read/write)
pvid->type = (u8)(((cmd >> 2) & 0xc) | (cmd >> 30));
if (pvid->type == 1) // vram
pvid->type |= pvid->reg[1] & 0x80; // 128k
// Get address 0x3fff0003
addr = (cmd >> 16) & 0x3fff;
addr |= (cmd << 14) & 0xc000;
pvid->addr = (u16)addr;
pvid->addr_u = (u8)((cmd >> 2) & 1);
}
// VDP interface
static void DrawSync(int skip)
{
int lines = Pico.video.reg[1]&0x08 ? 240 : 224;
int last = Pico.m.scanline - (skip || blankline == Pico.m.scanline);
if (last < lines && !(PicoIn.opt & POPT_ALT_RENDERER) &&
!PicoIn.skipFrame && Pico.est.DrawScanline <= last) {
//elprintf(EL_ANOMALY, "sync");
if (blankline >= 0 && blankline < last) {
PicoDrawSync(blankline, 1);
blankline = -1;
}
PicoDrawSync(last, 0);
}
}
PICO_INTERNAL_ASM void PicoVideoWrite(unsigned int a,unsigned short d)
{
struct PicoVideo *pvid=&Pico.video;
//elprintf(EL_STATUS, "PicoVideoWrite [%06x] %04x [%u] @ %06x",
// a, d, SekCyclesDone(), SekPc);
a &= 0x1c;
switch (a)
{
case 0x00: // Data port 0 or 2
// try avoiding the sync..
if (Pico.m.scanline < (pvid->reg[1]&0x08 ? 240 : 224) && (pvid->reg[1]&0x40) &&
!(!pvid->pending &&
((pvid->command & 0xc00000f0) == 0x40000010 && PicoMem.vsram[pvid->addr>>1] == d))
)
DrawSync(0);
if (pvid->pending) {
CommandChange();
pvid->pending=0;
}
if (!(PicoIn.opt&POPT_DIS_VDP_FIFO))
{
fifo_data[++fifo_dx&3] = d;
SekCyclesBurnRun(PicoVideoFIFOWrite(1, pvid->type == 1, 0, PVS_CPUWR));
elprintf(EL_ASVDP, "VDP data write: [%04x] %04x [%u] {%i} @ %06x",
Pico.video.addr, d, SekCyclesDone(), Pico.video.type, SekPc);
}
VideoWrite(d);
// start DMA fill on write. NB VSRAM and CRAM fills use wrong FIFO data.
if ((pvid->status & (PVS_DMAPEND|PVS_DMAFILL)) == (PVS_DMAPEND|PVS_DMAFILL))
DmaFill(fifo_data[(fifo_dx + !!(pvid->type&~0x81))&3]);
break;
case 0x04: // Control (command) port 4 or 6
if (pvid->pending)
{
// Low word of command:
if (!(pvid->reg[1]&0x10))
d = (d&~0x80)|(pvid->command&0x80);
pvid->command &= 0xffff0000;
pvid->command |= d;
pvid->pending = 0;
CommandChange();
// Check for dma:
if (d & 0x80) {
DrawSync(0);
CommandDma();
}
}
else
{
if ((d&0xc000)==0x8000)
{
// Register write:
int num=(d>>8)&0x1f;
int dold=pvid->reg[num];
int skip=0;
pvid->type=0; // register writes clear command (else no Sega logo in Golden Axe II)
if (num > 0x0a && !(pvid->reg[1]&4)) {
elprintf(EL_ANOMALY, "%02x written to reg %02x in SMS mode @ %06x", d, num, SekPc);
return;
}
if (num == 0 && !(pvid->reg[0]&2) && (d&2))
hvlatch = PicoVideoRead(0x08);
if (num == 1 && ((pvid->reg[1]^d)&0x40)) {
PicoVideoFIFOMode(d & 0x40);
// handle line blanking before line rendering
if (SekCyclesDone() - Pico.t.m68c_line_start <= 488-390) {
skip = 1;
blankline = d&0x40 ? -1 : Pico.m.scanline;
}
}
DrawSync(skip);
pvid->reg[num]=(unsigned char)d;
switch (num)
{
case 0x00:
elprintf(EL_INTSW, "hint_onoff: %i->%i [%u] pend=%i @ %06x", (dold&0x10)>>4,
(d&0x10)>>4, SekCyclesDone(), (pvid->pending_ints&0x10)>>4, SekPc);
goto update_irq;
case 0x01:
elprintf(EL_INTSW, "vint_onoff: %i->%i [%u] pend=%i @ %06x", (dold&0x20)>>5,
(d&0x20)>>5, SekCyclesDone(), (pvid->pending_ints&0x20)>>5, SekPc);
if (!(pvid->status & PVS_VB2))
pvid->status &= ~SR_VB;
pvid->status |= ((d >> 3) ^ SR_VB) & SR_VB; // forced blanking
goto update_irq;
case 0x05:
//elprintf(EL_STATUS, "spritep moved to %04x", (unsigned)(Pico.video.reg[5]&0x7f) << 9);
if (d^dold) Pico.est.rendstatus |= PDRAW_SPRITES_MOVED;
break;
case 0x0c:
// renderers should update their palettes if sh/hi mode is changed
if ((d^dold)&8) Pico.m.dirtyPal = 1;
break;
}
return;
update_irq:
#ifndef EMU_CORE_DEBUG
// update IRQ level
if (!SekShouldInterrupt()) // hack
{
int lines, pints, irq = 0;
lines = (pvid->reg[1] & 0x20) | (pvid->reg[0] & 0x10);
pints = pvid->pending_ints & lines;
if (pints & 0x20) irq = 6;
else if (pints & 0x10) irq = 4;
SekInterrupt(irq); // update line
// this is broken because cost of current insn isn't known here
if (irq) SekEndRun(21); // make it delayed
}
#endif
}
else
{
// High word of command:
pvid->command&=0x0000ffff;
pvid->command|=d<<16;
pvid->pending=1;
}
}
break;
// case 0x08: // 08 0a - HV counter - lock up
// case 0x0c: // 0c 0e - HV counter - lock up
// case 0x10: // 10 12 - PSG - handled by caller
// case 0x14: // 14 16 - PSG - handled by caller
// case 0x18: // 18 1a - no effect?
case 0x1c: // 1c 1e - debug
pvid->debug = d;
pvid->debug_p = 0;
if (d & (1 << 6)) {
pvid->debug_p |= PVD_KILL_A | PVD_KILL_B;
pvid->debug_p |= PVD_KILL_S_LO | PVD_KILL_S_HI;
}
switch ((d >> 7) & 3) {
case 1:
pvid->debug_p &= ~(PVD_KILL_S_LO | PVD_KILL_S_HI);
pvid->debug_p |= PVD_FORCE_S;
break;
case 2:
pvid->debug_p &= ~PVD_KILL_A;
pvid->debug_p |= PVD_FORCE_A;
break;
case 3:
pvid->debug_p &= ~PVD_KILL_B;
pvid->debug_p |= PVD_FORCE_B;
break;
}
break;
}
}
static u32 VideoSr(const struct PicoVideo *pv)
{
unsigned int c, d = pv->status;
unsigned int hp = pv->reg[12]&1 ? 32:40; // HBLANK start
unsigned int hl = pv->reg[12]&1 ? 94:84; // HBLANK length
c = SekCyclesDone();
if (c - Pico.t.m68c_line_start - hp < hl)
d |= SR_HB;
PicoVideoFIFOSync(c-Pico.t.m68c_line_start);
if (pv->status & SR_DMA)
d |= SR_EMPT; // unused by DMA, or rather flags not updated?
else if (fifo_total >= 4)
d |= SR_FULL;
else if (!fifo_total)
d |= SR_EMPT;
return d;
}
PICO_INTERNAL_ASM unsigned int PicoVideoRead(unsigned int a)
{
a &= 0x1c;
if (a == 0x04) // control port
{
struct PicoVideo *pv = &Pico.video;
unsigned int d = VideoSr(pv);
if (pv->pending) {
CommandChange();
pv->pending = 0;
}
elprintf(EL_SR, "SR read: %04x [%u] @ %06x", d, SekCyclesDone(), SekPc);
return d;
}
// H-counter info (based on Generator):
// frame:
// | <- hblank? -> |
// start <416> hint <36> hdisplay <38> end // CPU cycles
// |---------...---------|------------|-------------|
// 0 B6 E4 FF // 40 cells
// 0 93 E8 FF // 32 cells
// Gens (?) v-render
// start <hblank=84> hint hdisplay <404> |
// |---------------------|--------------------------|
// E4 (hc[0x43]==0) 07 B1 // 40
// E8 (hc[0x45]==0) 05 91 // 32
// check: Sonic 3D Blast bonus, Cannon Fodder, Chase HQ II, 3 Ninjas kick back, Road Rash 3, Skitchin', Wheel of Fortune
if ((a&0x1c)==0x08)
{
unsigned int d;
d = (SekCyclesDone() - Pico.t.m68c_line_start) & 0x1ff; // FIXME
if (Pico.video.reg[0]&2)
d = hvlatch;
else if (Pico.video.reg[12]&1)
d = hcounts_40[d] | (Pico.video.v_counter << 8);
else d = hcounts_32[d] | (Pico.video.v_counter << 8);
elprintf(EL_HVCNT, "hv: %02x %02x [%u] @ %06x", d, Pico.video.v_counter, SekCyclesDone(), SekPc);
return d;
}
if (a==0x00) // data port
{
return VideoRead();
}
return 0;
}
unsigned char PicoVideoRead8DataH(void)
{
return VideoRead() >> 8;
}
unsigned char PicoVideoRead8DataL(void)
{
return VideoRead();
}
unsigned char PicoVideoRead8CtlH(void)
{
u8 d = VideoSr(&Pico.video) >> 8;
if (Pico.video.pending) {
CommandChange();
Pico.video.pending = 0;
}
elprintf(EL_SR, "SR read (h): %02x @ %06x", d, SekPc);
return d;
}
unsigned char PicoVideoRead8CtlL(void)
{
u8 d = VideoSr(&Pico.video);
if (Pico.video.pending) {
CommandChange();
Pico.video.pending = 0;
}
elprintf(EL_SR, "SR read (l): %02x @ %06x", d, SekPc);
return d;
}
unsigned char PicoVideoRead8HV_H(void)
{
elprintf(EL_HVCNT, "vcounter: %02x [%u] @ %06x", Pico.video.v_counter, SekCyclesDone(), SekPc);
return Pico.video.v_counter;
}
// FIXME: broken
unsigned char PicoVideoRead8HV_L(void)
{
u32 d = (SekCyclesDone() - Pico.t.m68c_line_start) & 0x1ff; // FIXME
if (Pico.video.reg[12]&1)
d = hcounts_40[d];
else d = hcounts_32[d];
elprintf(EL_HVCNT, "hcounter: %02x [%u] @ %06x", d, SekCyclesDone(), SekPc);
return d;
}
// vim:shiftwidth=2:ts=2:expandtab
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