// license:BSD-3-Clause
// copyright-holders:Curt Coder, hap
/**********************************************************************
PLA (Programmable Logic Array) emulation
**********************************************************************/
#include "emu.h"
#include "pla.h"
#include "jedparse.h"
#include "plaparse.h"
#define LOG_TERMS (1U << 1)
//#define VERBOSE (LOG_TERMS)
#include "logmacro.h"
DEFINE_DEVICE_TYPE(PLA, pla_device, "pla", "PLA")
DEFINE_DEVICE_TYPE(PLS100, pls100_device, "pls100", "82S100-series PLA")
DEFINE_DEVICE_TYPE(MOS8721, mos8721_device, "mos8721", "MOS 8721 PLA")
//-------------------------------------------------
// pla_device - constructor
//-------------------------------------------------
pla_device::pla_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, type, tag, owner, clock)
, m_region(*this, DEVICE_SELF)
, m_format(FMT::JEDBIN)
, m_inputs(0)
, m_outputs(0)
, m_terms(0)
, m_input_mask(0)
, m_xor(0)
, m_cache_size(0), m_cache2_ptr(0)
{
}
pla_device::pla_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: pla_device(mconfig, PLA, tag, owner, clock)
{
}
pls100_device::pls100_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: pla_device(mconfig, PLS100, tag, owner, clock)
{
set_num_inputs(16);
set_num_outputs(8);
set_num_terms(48);
}
mos8721_device::mos8721_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: pla_device(mconfig, MOS8721, tag, owner, clock)
{
// TODO: actual number of terms is unknown
set_num_inputs(27);
set_num_outputs(18);
set_num_terms(379);
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void pla_device::device_start()
{
assert(m_terms < MAX_TERMS);
assert(m_inputs < 32 && m_outputs <= 32);
if (m_input_mask == 0)
m_input_mask = ((uint64_t)1 << m_inputs) - 1;
m_input_mask = ((uint64_t)m_input_mask << 32) | m_input_mask;
m_cache_size = 1 << ((m_inputs > MAX_CACHE_BITS) ? MAX_CACHE_BITS : m_inputs);
m_cache.resize(m_cache_size);
reinit();
}
bool pla_device::reinit()
{
int result = parse_fusemap();
// initialize cache
m_cache2_ptr = 0;
for (auto & elem : m_cache2)
elem = 0x80000000;
int csize = m_cache_size;
m_cache_size = 0;
for (int i = 0; i < csize; i++)
m_cache[i] = read(i);
m_cache_size = csize;
return result == JEDERR_NONE;
}
//-------------------------------------------------
// parse_fusemap -
//-------------------------------------------------
int pla_device::parse_fusemap()
{
jed_data jed;
int result = JEDERR_NONE;
// read pla file
auto file = util::ram_read(m_region->base(), m_region->bytes());
if (file)
{
switch (m_format)
{
case FMT::JEDBIN:
result = jedbin_parse(*file, &jed);
break;
case FMT::BERKELEY:
result = pla_parse(*file, &jed);
break;
}
}
if (!file || result != JEDERR_NONE)
{
for (int p = 0; p < m_terms; p++)
{
m_term[p].and_mask = 0;
m_term[p].or_mask = 0;
}
logerror("%s PLA parse error %d!\n", tag(), result);
return result;
}
// parse it
uint32_t fusenum = 0;
for (int p = 0; p < m_terms; p++)
{
term *term = &m_term[p];
// AND mask
term->and_mask = 0;
for (int i = 0; i < m_inputs; i++)
{
// complement
term->and_mask |= (uint64_t)jed_get_fuse(&jed, fusenum++) << (i + 32);
// true
term->and_mask |= (uint64_t)jed_get_fuse(&jed, fusenum++) << i;
}
// OR mask
term->or_mask = 0;
for (int f = 0; f < m_outputs; f++)
{
term->or_mask |= !jed_get_fuse(&jed, fusenum++) << f;
}
term->or_mask <<= 32;
LOGMASKED(LOG_TERMS, "F |= %0*X if (I & %0*X) == zeroes and (I & %0*X) == ones [term %d%s]\n",
(m_outputs + 3) / 4,
term->or_mask >> 32,
(m_inputs + 3) / 4,
(term->and_mask ^ m_input_mask) >> 32,
(m_inputs + 3) / 4,
uint32_t(term->and_mask ^ m_input_mask),
p,
(~term->and_mask & (~term->and_mask >> 32) & m_input_mask) == 0 ? "" : ", ignored");
}
// XOR mask
m_xor = 0;
for (int f = 0; f < m_outputs; f++)
{
m_xor |= jed_get_fuse(&jed, fusenum++) << f;
}
m_xor <<= 32;
LOGMASKED(LOG_TERMS, "F ^= %0*X\n", (m_outputs + 3) / 4, m_xor >> 32);
return result;
}
//-------------------------------------------------
// read -
//-------------------------------------------------
uint32_t pla_device::read(uint32_t input)
{
// try the cache first
if (input < m_cache_size)
return m_cache[input];
for (auto cache2_entry : m_cache2)
{
if ((uint32_t)cache2_entry == input)
{
// cache2 hit
return cache2_entry >> 32;
}
}
// cache miss, process terms
uint64_t inputs = ((~(uint64_t)input << 32) | input) & m_input_mask;
uint64_t s = 0;
for (int i = 0; i < m_terms; ++i)
{
term* term = &m_term[i];
if ((term->and_mask | inputs) == m_input_mask)
{
s |= term->or_mask;
}
}
s ^= m_xor;
// store output in cache2
m_cache2[m_cache2_ptr] = s | input;
++m_cache2_ptr &= (CACHE2_SIZE - 1);
return s >> 32;
}