dingusppc/devices/memctrl/hmc.cpp
2021-10-23 21:00:31 +02:00

71 lines
2.0 KiB
C++

/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-21 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/** Highspeed Memory Controller emulation.
Author: Max Poliakovski
*/
#include <devices/memctrl/hmc.h>
HMC::HMC() : MemCtrlBase()
{
this->name = "Highspeed Memory Controller";
/* add memory mapped I/O region for the HMC control register */
add_mmio_region(0x50F40000, 0x10000, this);
this->config_reg = 0ULL;
this->bit_pos = 0;
}
bool HMC::supports_type(HWCompType type) {
if (type == HWCompType::MEM_CTRL || type == HWCompType::MMIO_DEV) {
return true;
} else {
return false;
}
}
uint32_t HMC::read(uint32_t reg_start, uint32_t offset, int size)
{
if (!offset)
return !!(this->config_reg & (1ULL << this->bit_pos++));
else
return 0; /* FIXME: what should be returned for invalid offsets? */
}
void HMC::write(uint32_t reg_start, uint32_t offset, uint32_t value, int size)
{
uint64_t bit;
switch(offset) {
case 0:
bit = 1ULL << this->bit_pos++;
this->config_reg = (value & 1) ? this->config_reg | bit :
this->config_reg & ~bit;
break;
case 8: /* writing to HMCBase + 8 resets internal bit position */
this->bit_pos = 0;
break;
}
}