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Attmept full ADC implementation.

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This commit is contained in:
Thomas Harte
2025-09-18 12:21:25 -04:00
parent 26b1ef247b
commit 4c49ffe3d1
3 changed files with 69 additions and 11 deletions
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53
Components/uPD7002/uPD7002.cpp
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@@ -10,22 +10,61 @@
using namespace NEC;
uPD7002::uPD7002(HalfCycles) {
uPD7002::uPD7002(const HalfCycles clock_rate) {
// Per the BBC AUG: "8 bit conversions typically take 4 ms to complete whereas 10 bit
// conversions typically take 10 ms to complete".
fast_period_ = clock_rate / 250;
slow_period_ = clock_rate / 100;
}
void uPD7002::run_for(HalfCycles) {
void uPD7002::run_for(const HalfCycles count) {
if(!conversion_time_remaining_) {
return;
}
if(count >= conversion_time_remaining_) {
conversion_time_remaining_ = HalfCycles(0);
interrupt_ = true;
result_ = uint16_t(inputs_[channel_] * 65535.0f) & (high_precision_ ? 0xfff0 : 0xff00);
if(delegate_) delegate_->did_change_interrupt_status(*this);
return;
}
conversion_time_remaining_ -= count;
}
bool uPD7002::interrupt() const {
return false;
return interrupt_;
}
void uPD7002::write(const uint16_t address, const uint8_t value) {
(void)address;
(void)value;
if(!address) {
channel_ = value & 3;
high_precision_ = value & 8;
conversion_time_remaining_ = high_precision_ ? slow_period_ : fast_period_;
return;
}
}
uint8_t uPD7002::read(const uint16_t address) {
(void)address;
return 0xff;
if(!address) {
return status();
}
if(address & 1) {
interrupt_ = false;
if(delegate_) delegate_->did_change_interrupt_status(*this);
return uint8_t(result_ >> 8);
} else {
return uint8_t(result_);
}
}
uint8_t uPD7002::status() const {
return
channel_ |
(high_precision_ ? 8 : 0) |
((result_ >> 10) & 0x30) |
(conversion_time_remaining_ > HalfCycles(0) ? 0x00 : 0x40) |
(interrupt_ ? 0x00 : 0x80);
}