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Switches to a more explicit tokeniser, to allow for greater flexibility momentarily.

This commit is contained in:
Thomas Harte 2019-03-30 23:11:39 -04:00
parent bc6349f823
commit cb240cd32a

View File

@ -9,6 +9,7 @@
#include "../68000.hpp"
#include <algorithm>
#include <sstream>
namespace CPU {
namespace MC68000 {
@ -35,7 +36,7 @@ struct ProcessorStorageConstructor {
return (mode == 7) ? (0x10 | reg) : mode;
}
#define pseq(x, m) ((((m)&0xff) == 0x06) || (((m)&0xff) == 0x13) ? "n" x : x)
#define pseq(x, m) ((((m)&0xff) == 0x06) || (((m)&0xff) == 0x13) ? "n " x : x)
/*!
Installs BusSteps that implement the described program into the relevant
@ -79,129 +80,118 @@ struct ProcessorStorageConstructor {
The user should fill in the steps necessary to get data into or extract
data from those.
*/
size_t assemble_program(const char *access_pattern, const std::vector<uint32_t *> &addresses = {}, bool read_full_words = true) {
size_t assemble_program(std::string access_pattern, const std::vector<uint32_t *> &addresses = {}, bool read_full_words = true) {
auto address_iterator = addresses.begin();
RegisterPair32 *scratch_data_read = storage_.bus_data_;
RegisterPair32 *scratch_data_write = storage_.bus_data_;
using Action = BusStep::Action;
std::vector<BusStep> steps;
std::stringstream stream(access_pattern);
// Parse the access pattern to build microcycles.
while(*access_pattern) {
// Tokenise the access pattern by splitting on spaces.
std::string token;
while(stream >> token) {
ProcessorBase::BusStep step;
switch(*access_pattern) {
case '\t': case ' ': // White space acts as a no-op; it's for clarity only.
++access_pattern;
break;
case 'n': // This might be a plain NOP cycle, in which some internal calculation occurs,
// or it might pair off with something afterwards.
switch(access_pattern[1]) {
default: // This is probably a pure NOP; if what comes after this 'n' isn't actually
// valid, it should be caught in the outer switch the next time around the loop.
steps.push_back(step);
++access_pattern;
break;
case '-': // This is two NOPs in a row.
steps.push_back(step);
steps.push_back(step);
access_pattern += 2;
break;
case 'F': // Fetch SSP MSW.
case 'f': // Fetch SSP LSW.
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | Microcycle::Read | Microcycle::IsProgram; // IsProgram is a guess.
step.microcycle.address = &storage_.effective_address_[0].full;
step.microcycle.value = isupper(access_pattern[1]) ? &storage_.stack_pointers_[1].halves.high : &storage_.stack_pointers_[1].halves.low;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation = Microcycle::SelectWord | Microcycle::Read | Microcycle::IsProgram;
step.action = Action::IncrementEffectiveAddress0;
steps.push_back(step);
access_pattern += 2;
break;
case 'V': // Fetch exception vector low.
case 'v': // Fetch exception vector high.
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | Microcycle::Read | Microcycle::IsProgram; // IsProgram is a guess.
step.microcycle.address = &storage_.effective_address_[0].full;
step.microcycle.value = isupper(access_pattern[1]) ? &storage_.program_counter_.halves.high : &storage_.program_counter_.halves.low;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation |= Microcycle::SelectWord | Microcycle::Read | Microcycle::IsProgram;
step.action = Action::IncrementEffectiveAddress0;
steps.push_back(step);
access_pattern += 2;
break;
case 'p': // Fetch from the program counter into the prefetch queue.
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | Microcycle::Read | Microcycle::IsProgram;
step.microcycle.address = &storage_.program_counter_.full;
step.microcycle.value = &storage_.prefetch_queue_.halves.low;
step.action = Action::AdvancePrefetch;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation |= Microcycle::SelectWord | Microcycle::Read | Microcycle::IsProgram;
step.action = Action::IncrementProgramCounter;
steps.push_back(step);
access_pattern += 2;
break;
case 'r': // Fetch LSW (or only) word (/byte)
case 'R': // Fetch MSW word
case 'w': // Store LSW (or only) word (/byte)
case 'W': { // Store MSW word
const bool is_read = tolower(access_pattern[1]) == 'r';
RegisterPair32 **scratch_data = is_read ? &scratch_data_read : &scratch_data_write;
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | (is_read ? Microcycle::Read : 0);
step.microcycle.address = *address_iterator;
step.microcycle.value = isupper(access_pattern[1]) ? &(*scratch_data)->halves.high : &(*scratch_data)->halves.low;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation |= (read_full_words ? Microcycle::SelectWord : Microcycle::SelectByte) | (is_read ? Microcycle::Read : 0);
if(access_pattern[1] == 'R') {
step.action = Action::IncrementEffectiveAddress0;
}
if(access_pattern[1] == 'W') {
step.action = Action::IncrementEffectiveAddress1;
}
steps.push_back(step);
if(!isupper(access_pattern[1])) {
++(*scratch_data);
++address_iterator;
}
access_pattern += 2;
} break;
}
break;
case '_': // Indicates the reset cycle.
step.microcycle.length = HalfCycles(248);
step.microcycle.operation = Microcycle::Reset;
// Do nothing (possibly twice).
if(token == "n" || token == "nn") {
steps.push_back(step);
if(token.size() == 2) {
steps.push_back(step);
++access_pattern;
break;
default:
std::cerr << "MC68000 program builder; Unknown access type " << *access_pattern << std::endl;
assert(false);
}
continue;
}
// Fetch SSP.
if(token == "nF" || token == "nf") {
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | Microcycle::Read | Microcycle::IsProgram; // IsProgram is a guess.
step.microcycle.address = &storage_.effective_address_[0].full;
step.microcycle.value = isupper(token[1]) ? &storage_.stack_pointers_[1].halves.high : &storage_.stack_pointers_[1].halves.low;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation = Microcycle::SelectWord | Microcycle::Read | Microcycle::IsProgram;
step.action = Action::IncrementEffectiveAddress0;
steps.push_back(step);
continue;
}
// Fetch exception vector.
if(token == "nV" || token == "nv") {
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | Microcycle::Read | Microcycle::IsProgram; // IsProgram is a guess.
step.microcycle.address = &storage_.effective_address_[0].full;
step.microcycle.value = isupper(token[1]) ? &storage_.program_counter_.halves.high : &storage_.program_counter_.halves.low;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation |= Microcycle::SelectWord | Microcycle::Read | Microcycle::IsProgram;
step.action = Action::IncrementEffectiveAddress0;
steps.push_back(step);
continue;
}
// Fetch from the program counter into the prefetch queue.
if(token == "np") {
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | Microcycle::Read | Microcycle::IsProgram;
step.microcycle.address = &storage_.program_counter_.full;
step.microcycle.value = &storage_.prefetch_queue_.halves.low;
step.action = Action::AdvancePrefetch;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation |= Microcycle::SelectWord | Microcycle::Read | Microcycle::IsProgram;
step.action = Action::IncrementProgramCounter;
steps.push_back(step);
continue;
}
// The reset cycle.
if(token == "_") {
step.microcycle.length = HalfCycles(248);
step.microcycle.operation = Microcycle::Reset;
steps.push_back(step);
continue;
}
// A standard read or write.
if(token == "nR" || token == "nr" || token == "nW" || token == "nw") {
const bool is_read = tolower(access_pattern[1]) == 'r';
RegisterPair32 **scratch_data = is_read ? &scratch_data_read : &scratch_data_write;
step.microcycle.length = HalfCycles(5);
step.microcycle.operation = Microcycle::NewAddress | (is_read ? Microcycle::Read : 0);
step.microcycle.address = *address_iterator;
step.microcycle.value = isupper(token[1]) ? &(*scratch_data)->halves.high : &(*scratch_data)->halves.low;
steps.push_back(step);
step.microcycle.length = HalfCycles(3);
step.microcycle.operation |= (read_full_words ? Microcycle::SelectWord : Microcycle::SelectByte) | (is_read ? Microcycle::Read : 0);
if(token[1] == 'R') {
step.action = Action::IncrementEffectiveAddress0;
}
if(token[1] == 'W') {
step.action = Action::IncrementEffectiveAddress1;
}
steps.push_back(step);
if(!isupper(access_pattern[1])) {
++(*scratch_data);
++address_iterator;
}
continue;
}
std::cerr << "MC68000 program builder; Unknown access token " << token << std::endl;
assert(false);
}
// Add a final 'ScheduleNextProgram' sentinel.