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Implement SCSI Pseudo-DMA register on PDM.

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This commit is contained in:
Maxim Poliakovski 2022-10-31 23:20:39 +01:00
parent 7ab44886c4
commit 6ffe28a8a4
3 changed files with 38 additions and 3 deletions
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30
devices/common/scsi/sc53c94.cpp
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@ -152,6 +152,36 @@ void Sc53C94::write(uint8_t reg_offset, uint8_t value)
}
}
uint16_t Sc53C94::pseudo_dma_read()
{
uint16_t data_word;
bool is_done = false;
if (this->data_fifo_pos >= 2) {
// remove one word from FIFO
data_word = (this->data_fifo[0] << 8) | this->data_fifo[1];
this->data_fifo_pos -= 2;
std:memmove(this->data_fifo, &this->data_fifo[2], this->data_fifo_pos);
// update DMA status
if ((this->cmd_fifo[0] & 0x80)) {
this->xfer_count -= 2;
if (!this->xfer_count) {
is_done = true;
this->cur_state = SeqState::XFER_END;
this->sequencer();
}
}
}
// see if we need to refill FIFO
if (!this->data_fifo_pos && !is_done) {
this->sequencer();
}
return data_word;
}
void Sc53C94::update_command_reg(uint8_t cmd)
{
if (this->on_reset && (cmd & 0x7F) != CMD_NOP) {

5
devices/common/scsi/sc53c94.h
View File

@ -144,8 +144,9 @@ public:
int device_postinit();
// 53C94 registers access
uint8_t read(uint8_t reg_offset);
void write(uint8_t reg_offset, uint8_t value);
uint8_t read(uint8_t reg_offset);
void write(uint8_t reg_offset, uint8_t value);
uint16_t pseudo_dma_read();
// ScsiDevice methods
void notify(ScsiBus* bus_obj, ScsiMsg msg_type, int param);

6
devices/ioctrl/amic.cpp
View File

@ -115,7 +115,11 @@ uint32_t AMIC::read(uint32_t rgn_start, uint32_t offset, int size)
case 0xA: // MACE registers
return this->mace->read((offset >> 4) & 0x1F);
case 0x10: // SCSI registers
return this->scsi->read((offset >> 4) & 0xF);
if (offset & 0x100) {
return this->scsi->pseudo_dma_read();
} else {
return this->scsi->read((offset >> 4) & 0xF);
}
case 0x14: // Sound registers
switch (offset) {
case AMICReg::Snd_Stat_0: