160 lines
3.6 KiB
C++
160 lines
3.6 KiB
C++
#include <cassert>
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#include <cstring>
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#include "gen.h"
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#include "log.h"
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#include "mmu.h"
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#include "utils.h"
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mmu::mmu()
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{
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}
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mmu::~mmu()
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{
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}
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void mmu::reset()
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{
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memset(pages, 0x00, sizeof pages);
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CPUERR = MMR0 = MMR1 = MMR2 = MMR3 = PIR = CSR = 0;
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}
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uint16_t mmu::read_pdr(const uint32_t a, const int run_mode, const word_mode_t word_mode, const bool peek_only)
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{
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int page = (a >> 1) & 7;
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bool is_d = a & 16;
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uint16_t t = pages[run_mode][is_d][page].pdr;
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if (!peek_only)
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DOLOG(debug, false, "MMU READ-I/O PDR run-mode %d: %c for %d: %o", run_mode, is_d ? 'D' : 'I', page, t);
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return word_mode ? (a & 1 ? t >> 8 : t & 255) : t;
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}
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uint16_t mmu::read_par(const uint32_t a, const int run_mode, const word_mode_t word_mode, const bool peek_only)
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{
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int page = (a >> 1) & 7;
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bool is_d = a & 16;
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uint16_t t = pages[run_mode][is_d][page].par;
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if (!peek_only)
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DOLOG(debug, false, "MMU READ-I/O PAR run-mode %d: %c for %d: %o (phys: %07o)", run_mode, is_d ? 'D' : 'I', page, t, t * 64);
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return word_mode ? (a & 1 ? t >> 8 : t & 255) : t;
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}
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void mmu::setMMR0(uint16_t value)
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{
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value &= ~(3 << 10); // bit 10 & 11 always read as 0
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if (value & 1)
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value &= ~(7l << 13); // reset error bits
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if (MMR0 & 0160000) {
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if ((value & 1) == 0)
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value &= 254; // bits 7...1 are protected
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}
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// TODO if bit 15/14/13 are set (either of them), then do not modify bit 1...7
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MMR0 = value;
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}
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void mmu::setMMR0Bit(const int bit)
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{
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assert(bit != 10 && bit != 11);
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assert(bit < 16 && bit >= 0);
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MMR0 |= 1 << bit;
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}
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void mmu::clearMMR0Bit(const int bit)
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{
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assert(bit != 10 && bit != 11);
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assert(bit < 16 && bit >= 0);
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MMR0 &= ~(1 << bit);
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}
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void mmu::setMMR2(const uint16_t value)
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{
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MMR2 = value;
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}
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void mmu::setMMR3(const uint16_t value)
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{
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MMR3 = value;
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}
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bool mmu::get_use_data_space(const int run_mode) const
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{
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constexpr const int di_ena_mask[4] = { 4, 2, 0, 1 };
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return !!(MMR3 & di_ena_mask[run_mode]);
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}
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void mmu::clearMMR1()
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{
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MMR1 = 0;
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}
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void mmu::addToMMR1(const int8_t delta, const uint8_t reg)
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{
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assert(reg >= 0 && reg <= 7);
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assert(delta >= -2 && delta <= 2);
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assert((getMMR0() & 0160000) == 0); // MMR1 should not be locked
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#if defined(ESP32)
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// if (MMR1 > 255)
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// esp_backtrace_print(32);
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#else
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if (MMR1 > 255) {
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extern FILE *lfh;
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fflush(lfh);
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}
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assert(MMR1 < 256);
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#endif
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MMR1 <<= 8;
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MMR1 |= (delta & 31) << 3;
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MMR1 |= reg;
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}
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void mmu::write_pdr(const uint32_t a, const int run_mode, const uint16_t value, const word_mode_t word_mode)
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{
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bool is_d = a & 16;
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int page = (a >> 1) & 7;
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if (word_mode == wm_byte) {
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assert(a != 0 || value < 256);
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update_word(&pages[run_mode][is_d][page].pdr, a & 1, value);
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}
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else {
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pages[run_mode][is_d][page].pdr = value;
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}
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pages[run_mode][is_d][page].pdr &= ~(32768 + 128 /*A*/ + 64 /*W*/ + 32 + 16); // set bit 4, 5 & 15 to 0 as they are unused and A/W are set to 0 by writes
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DOLOG(debug, false, "mmu WRITE-I/O PDR run-mode %d: %c for %d: %o [%d]", run_mode, is_d ? 'D' : 'I', page, value, word_mode);
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}
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void mmu::write_par(const uint32_t a, const int run_mode, const uint16_t value, const word_mode_t word_mode)
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{
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bool is_d = a & 16;
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int page = (a >> 1) & 7;
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if (word_mode == wm_byte)
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update_word(&pages[run_mode][is_d][page].par, a & 1, value);
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else
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pages[run_mode][is_d][page].par = value;
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pages[run_mode][is_d][page].pdr &= ~(128 /*A*/ + 64 /*W*/); // reset PDR A/W when PAR is written to
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DOLOG(debug, false, "mmu WRITE-I/O PAR run-mode %d: %c for %d: %o (%07o)", run_mode, is_d ? 'D' : 'I', page, word_mode == wm_byte ? value & 0xff : value, pages[run_mode][is_d][page].par * 64);
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}
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