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(MESS) geneve: Implementing precise wait state behavior. (nw)

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This commit is contained in:
Michael Zapf 2013-10-27 17:09:50 +00:00
parent 44c0bac025
commit 86d7d3da82
2 changed files with 125 additions and 82 deletions
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198
src/mess/machine/ti99/genboard.c
View File

@ -100,6 +100,28 @@
for the GPL interpreter, and the external Memex memory. This switch
triggers a reset when changed.
Mapping
-------
Geneve mode
-----------
Video: f100 / f102 (mirror f108 / f10a) (read)
Mapper: f110 - f117
Keyboard: f118
Clock: f130 - f13f
Sound: f120
TI mode
-------
Mapper: 8000 - 8007
Keyboard: 8008 - 800f
Clock: 8010 - 801f
Video: 8800 / 8802
Speech: 9000 / 9400
Grom: 9800 / 9802
Waitstate handling
------------------
Waitstates are caused by a cleared READY line of the TMS9995 processor
@ -127,15 +149,11 @@
pulled down until the next clock pulse, which may take some value between
18 CPU cycles and 30 CPU cycles.
There is also a flag for video wait states. Waiting for video at first
means an access to a memory-mapped device, giving 1 or 2 WS, and an
additional 14 WS after the access. As said, these waitstates will run
unnoticed when the code is located in the on-chip RAM. This makes emulation
a bit non-straightforward.
These 14 WS are simulated by a timer device which is started together with
the video access, and when some external access occurs later, the
remaining time will be used to produce wait states.
The gate array is able to create wait states for video accesses. However,
these wait states are effective after the video access has been completed.
Wait states are not effective when the execution is running in on-chip
RAM. Additional wait states are requested by m_video_waitstates = true.
Without additional wait states, the video access takes the usual 1 or 2 WS.
Michael Zapf, October 2011
February 2012: rewritten as class, restructured
@ -249,17 +267,23 @@ WRITE8_MEMBER( geneve_mapper_device::write_grom )
void geneve_mapper_device::set_wait(int min)
{
// min = min + 1;
// Extra waitstates?
if (m_extra_waitstates && min < 4) min = 3;
m_waitcount = min;
if (m_waitcount > 0)
if (m_debug_no_ws) return;
if (m_extra_waitstates && min < 2) min = 2;
// need one more pass so that READY will be asserted again
m_waitcount = min + 1;
if (m_waitcount > 1)
{
if (VERBOSE>7) LOG("genboard: Pulling down READY line for %d cycles\n", m_waitcount);
if (VERBOSE>7) LOG("genboard: Pulling down READY line for %d cycles\n", min);
m_ready(CLEAR_LINE);
}
}
void geneve_mapper_device::set_ext_wait(int min)
{
if (m_debug_no_ws) return;
m_ext_waitcount = min;
}
/************************************************************************
Called by the address map
************************************************************************/
@ -310,12 +334,14 @@ READ8_MEMBER( geneve_mapper_device::readm )
if (space.debugger_access())
{
dec = &debug;
decode(space, offset, false, true, dec);
m_debug_no_ws = true;
decode(space, offset, true, dec);
}
else
{
// Use the values found in the setaddress phase
dec = &m_decoded;
m_debug_no_ws = false;
}
switch (dec->function)
@ -323,6 +349,9 @@ READ8_MEMBER( geneve_mapper_device::readm )
case MLGVIDEO:
m_video->readz(space, dec->offset, &value, 0xff);
if (VERBOSE>7) LOG("genboard: Read video %04x -> %02x\n", dec->offset, value);
// Video wait states are created *after* the access
// Accordingly, they have no effect when execution is in onchip RAM
if (m_video_waitstates) set_ext_wait(16);
break;
case MLGMAPPER:
@ -377,6 +406,8 @@ READ8_MEMBER( geneve_mapper_device::readm )
// 1000 1000 0000 00x0
m_video->readz(space, dec->offset, &value, 0xff);
if (VERBOSE>7) LOG("genboard: Read video %04x -> %02x\n", dec->offset, value);
// See above
if (m_video_waitstates) set_ext_wait(16);
break;
case MLTSPEECH:
@ -470,11 +501,13 @@ WRITE8_MEMBER( geneve_mapper_device::writem )
if (space.debugger_access())
{
dec = &debug;
decode(space, offset, false, false, dec);
m_debug_no_ws = true;
decode(space, offset, false, dec);
}
else
{
// Use the values found in the setaddress phase
m_debug_no_ws = false;
dec = &m_decoded;
}
@ -486,6 +519,8 @@ WRITE8_MEMBER( geneve_mapper_device::writem )
// 1111 0001 0000 .cc0
m_video->write(space, dec->offset, data, 0xff);
if (VERBOSE>7) LOG("genboard: Write video %04x <- %02x\n", offset, data);
// See above
if (m_video_waitstates) set_ext_wait(16);
break;
case MLGMAPPER:
@ -527,6 +562,8 @@ WRITE8_MEMBER( geneve_mapper_device::writem )
// Initialize waitstate timer
m_video->write(space, dec->offset, data, 0xff);
if (VERBOSE>7) LOG("genboard: Write video %04x <- %02x\n", offset, data);
// See above
if (m_video_waitstates) set_ext_wait(16);
break;
case MLTSPEECH:
@ -608,7 +645,7 @@ WRITE8_MEMBER( geneve_mapper_device::writem )
}
}
void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setwait, bool read_mode, geneve_mapper_device::decdata* dec)
void geneve_mapper_device::decode(address_space& space, offs_t offset, bool read_mode, geneve_mapper_device::decdata* dec)
{
dec->function = 0;
dec->offset = offset;
@ -631,14 +668,8 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// 1111 0001 0000 1000
// 1111 0001 0000 1010
// 1 WS is always added; any pending video wait states are canceled
if (setwait) set_wait(1);
// Initialize wait state timer
// Create 16 wait states (2 more than expected, experimenting)
if (m_video_waitstates && setwait) set_wait(16);
dec->function = MLGVIDEO;
set_wait(1);
return;
}
if ((offset & 0xfff8)==0xf110)
@ -646,14 +677,14 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// mapper
dec->function = MLGMAPPER;
dec->offset = dec->offset & 0x0007;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfff8) == 0xf118)
{
// key
dec->function = MLGKEY;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfff0)==0xf130)
@ -663,7 +694,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// upper nibble is 0xf (probably because of the location at 0xf130?)
dec->function = MLGCLOCK;
dec->offset = dec->offset & 0x000f;
if (setwait) set_wait(1);
set_wait(1);
return;
}
}
@ -674,14 +705,14 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// mapper
dec->function = MLTMAPPER;
dec->offset = dec->offset & 0x0007;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfff8)== 0x8008)
{
// key
dec->function = MLTKEY;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfff0)==0x8010)
@ -689,7 +720,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// clock
dec->function = MLTCLOCK;
dec->offset = dec->offset & 0x000f;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfc01)==0x8800)
@ -699,11 +730,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// 1000 1000 0000 00x0
// 1 WS is always added; any pending video waitstates are canceled
dec->function = MLTVIDEO;
if (setwait) set_wait(1);
// Initialize waitstate timer
// Create 14 waitstates (+2, see above)
if (m_video_waitstates && setwait) set_wait(16);
set_wait(1);
return;
}
if ((offset & 0xfc01)==0x9000)
@ -715,7 +742,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
dec->function = MLTSPEECH;
dec->offset = offset | ((m_genmod)? 0x170000 : 0x070000);
m_peribox->setaddress_dbin(space, dec->offset, read_mode);
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfc01)==0x9800)
@ -724,7 +751,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// ++++ ++-- ---- ---+
// 1001 1000 0000 00x0
dec->function = MLTGROM;
if (setwait) set_wait(1);
set_wait(1);
return;
}
}
@ -757,7 +784,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// DRAM.
dec->physaddr = dec->physaddr & 0x07ffff;
dec->function = MPGDRAM;
if (setwait) set_wait(1);
set_wait(1);
return;
}
@ -765,7 +792,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
{
// On-board memory expansion for standard Geneve (never used)
dec->function = MPGEXP;
if (setwait) set_wait(1);
set_wait(1);
return;
}
@ -775,14 +802,14 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// mirrored for f0, f2, f4, ...; f1, f3, f5, ...
dec->function = MPGEPROM;
dec->physaddr = dec->physaddr & 0x003fff;
if (setwait) set_wait(0);
set_wait(0);
return;
}
if ((dec->physaddr & 0x180000)==0x180000)
{
dec->function = MPGSRAM;
if (setwait) set_wait(0);
set_wait(0);
return;
}
@ -790,7 +817,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// 0x000000-0x07ffff for the stock Geneve (AMC,AMB,AMA,A0 ...,A15)
// 0x000000-0x1fffff for the GenMod.(AME,AMD,AMC,AMB,AMA,A0 ...,A15)
// Add a wait state
if (setwait) set_wait(1);
set_wait(1);
dec->function = MPGBOX;
dec->physaddr = (dec->physaddr & 0x0007ffff); // 19 bit address (with AMA..AMC)
@ -805,7 +832,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// DRAM. One wait state.
dec->function = MPGMDRAM;
dec->physaddr = dec->physaddr & 0x07ffff;
if (!m_turbo && setwait) set_wait(1);
if (!m_turbo) set_wait(1);
return;
}
@ -815,7 +842,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// mirrored for f0, f2, f4, ...; f1, f3, f5, ...
dec->function = MPGMEPROM;
dec->physaddr = dec->physaddr & 0x003fff;
if (setwait) set_wait(0);
set_wait(0);
return;
}
@ -823,7 +850,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
dec->physaddr = (dec->physaddr & 0x001fffff); // 21 bit address for Genmod
dec->function = MPGMBOX;
if (!m_turbo && setwait) set_wait(1);
if (!m_turbo) set_wait(1);
// Check: Are waitstates completely turned off for turbo mode, or
// merely the waitstates for DRAM memory access and box access?
@ -840,17 +867,14 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
{
// 1 WS is always added; any pending video waitstates are canceled
dec->function = MLGVIDEO;
if (setwait) set_wait(1);
// Initialize waitstate timer
// Create 14 waitstates (+3, experimenting)
if (m_video_waitstates && setwait) set_wait(17);
set_wait(1);
return;
}
if ((offset & 0xfff8)==0xf110)
{
dec->function = MLGMAPPER;
dec->offset = dec->offset & 0x0007;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfff1)==0xf120)
@ -860,14 +884,14 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// the sound chip
// TODO: do it properly with the use of READY
dec->function = MLGSOUND;
if (setwait) set_wait(24);
set_wait(24);
return;
}
if ((offset & 0xfff0)==0xf130)
{
dec->function = MLGCLOCK;
dec->offset = dec->offset & 0x00f;
if (setwait) set_wait(1);
set_wait(1);
return;
}
}
@ -878,20 +902,20 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
{
dec->function = MLTMAPPER;
dec->offset = dec->offset & 0x0007;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfff0)==0x8010)
{
dec->function = MLTCLOCK;
dec->offset = dec->offset & 0x00f;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfc01)==0x9c00)
{
dec->function = MLTGROM;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((offset & 0xfc01)==0x8400)
@ -901,18 +925,14 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
// the sound chip
// TODO: do it properly with the use of READY-
dec->function = MLTSOUND;
if (setwait) set_wait(24);
set_wait(24);
return;
}
if ((offset & 0xfc01)==0x8c00)
{
// 1 WS is always added; any pending video waitstates are canceled
dec->function = MLTVIDEO;
if (setwait) set_wait(1);
// Initialize waitstate timer
// Create 14 waitstates (+3)
if (m_video_waitstates && setwait) set_wait(17);
set_wait(1);
return;
}
@ -921,7 +941,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
dec->function = MLTSPEECH;
dec->offset = dec->offset | ((m_genmod)? 0x170000 : 0x070000);
m_peribox->setaddress_dbin(space, dec->offset, read_mode);
if (setwait) set_wait(1);
set_wait(1);
return;
}
}
@ -941,7 +961,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
{
m_cartridge_secondpage = ((dec->offset & 0x0002)!=0);
if (VERBOSE>7) LOG("genboard: Set cartridge page %02x\n", m_cartridge_secondpage);
if (setwait) set_wait(1);
set_wait(1);
return;
}
else
@ -970,26 +990,26 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
{
dec->function = MPGDRAM;
dec->physaddr = dec->physaddr & 0x07ffff;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((dec->physaddr & 0x180000)==0x080000)
{
dec->function = MPGEXP;
if (setwait) set_wait(1);
set_wait(1);
return;
}
if ((dec->physaddr & 0x1e0000)==0x1e0000)
{
dec->function = MPGEPROM;
if (setwait) set_wait(0); // EPROM
set_wait(0); // EPROM
return;
}
if ((dec->physaddr & 0x180000)==0x180000)
{
dec->function = MPGSRAM;
if (setwait) set_wait(0); // SRAM
set_wait(0); // SRAM
return;
}
@ -1000,7 +1020,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
dec->function = MPGBOX;
dec->physaddr = (dec->physaddr & 0x0007ffff); // 19 bit address
m_peribox->setaddress_dbin(space, dec->physaddr, read_mode);
if (setwait) set_wait(1);
set_wait(1);
}
else
{
@ -1008,7 +1028,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
if ((dec->physaddr & 0x1e0000)==0x1e0000)
{ // EPROM, ignore
dec->function = MPGMEPROM;
if (setwait) set_wait(0);
set_wait(0);
return;
}
@ -1016,7 +1036,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
{
dec->function = MPGMDRAM;
dec->physaddr = dec->physaddr & 0x07ffff;
if (!m_turbo && setwait) set_wait(1);
if (!m_turbo) set_wait(1);
return;
}
@ -1024,7 +1044,7 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
dec->function = MPGMBOX;
dec->physaddr = (dec->physaddr & 0x001fffff); // 21 bit address for Genmod
m_peribox->setaddress_dbin(space, dec->physaddr, read_mode);
if (!m_turbo && setwait) set_wait(1);
if (!m_turbo) set_wait(1);
}
}
}
@ -1037,7 +1057,8 @@ void geneve_mapper_device::decode(address_space& space, offs_t offset, bool setw
SETOFFSET_MEMBER( geneve_mapper_device::setoffset )
{
if (VERBOSE>7) LOG("genboard: setoffset = %04x\n", offset);
decode(space, offset, true, m_read_mode, &m_decoded);
m_debug_no_ws = false;
decode(space, offset, m_read_mode, &m_decoded);
}
/*
@ -1046,11 +1067,30 @@ SETOFFSET_MEMBER( geneve_mapper_device::setoffset )
*/
WRITE_LINE_MEMBER( geneve_mapper_device::clock_in )
{
if (state==ASSERT_LINE && m_waitcount!=0)
if (state==ASSERT_LINE)
{
if (VERBOSE>5) LOG("genboard: clock\n");
m_waitcount--;
if (m_waitcount==0) m_ready(ASSERT_LINE);
if (m_waitcount!=0)
{
m_waitcount--;
if (m_waitcount==0)
{
if (VERBOSE>5) LOG("genboard: clock, asserting READY again\n");
m_ready(ASSERT_LINE);
}
else if (VERBOSE>5) LOG("genboard: clock, still waiting %d cycle(s)\n", m_waitcount);
}
else
{
// Now for the extra video wait states
// Notice that we let the READY line get asserted before.
if (m_ext_waitcount > 0)
{
if (VERBOSE>5) LOG("genboard: clock, going for %d extra waitstates.\n", m_ext_waitcount);
m_waitcount = m_ext_waitcount;
m_ext_waitcount = 0;
m_ready(CLEAR_LINE);
}
}
}
}
@ -1084,8 +1124,6 @@ void geneve_mapper_device::device_start()
m_geneve_mode = false;
m_direct_mode = true;
m_waitcount = 0;
}
void geneve_mapper_device::device_reset()
@ -1095,6 +1133,8 @@ void geneve_mapper_device::device_reset()
m_extra_waitstates = false;
m_video_waitstates = true;
m_read_mode = false;
m_waitcount = 0;
m_ext_waitcount = 0;
m_geneve_mode =false;
m_direct_mode = true;

9
src/mess/machine/ti99/genboard.h
View File

@ -133,8 +133,6 @@ public:
inline void set_video_waitstates(bool wait) { m_video_waitstates = wait; }
inline void set_extra_waitstates(bool wait) { m_extra_waitstates = wait; }
void set_wait(int min);
DECLARE_READ8_MEMBER( readm );
DECLARE_WRITE8_MEMBER( writem );
DECLARE_SETOFFSET_MEMBER( setoffset );
@ -157,11 +155,15 @@ private:
DECLARE_WRITE8_MEMBER( write_grom );
// wait states
void set_wait(int min);
void set_ext_wait(int min);
bool m_video_waitstates;
bool m_extra_waitstates;
bool m_read_mode;
bool m_debug_no_ws;
// Mapper function
typedef struct
{
@ -178,7 +180,7 @@ private:
bool m_cartridge7_writable;
int m_map[8];
void decode(address_space& space, offs_t offset, bool setwait, bool read_mode, decdata* dec);
void decode(address_space& space, offs_t offset, bool read_mode, decdata* dec);
decdata m_decoded;
// Genmod modifications
@ -194,6 +196,7 @@ private:
// Counter for the wait states.
int m_waitcount;
int m_ext_waitcount;
// Devices
mm58274c_device* m_clock;