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The 6522 is now a ClockReceiver.

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This commit is contained in:
Thomas Harte
2017-07-24 22:29:09 -04:00
parent 2912d7055b
commit efdac2ce8c
5 changed files with 25 additions and 37 deletions
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Components/6522/6522.hpp
+13 -25
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@@ -13,6 +13,8 @@
#include <typeinfo>
#include <cstdio>
#include "../ClockReceiver.hpp"
namespace MOS {
/*!
@@ -26,7 +28,7 @@ namespace MOS {
Consumers should derive their own curiously-recurring-template-pattern subclass,
implementing bus communications as required.
*/
template <class T> class MOS6522 {
template <class T> class MOS6522: public ClockReceiver<MOS6522<T>> {
private:
enum InterruptFlag: uint8_t {
CA2ActiveEdge = 1 << 0,
@@ -250,32 +252,22 @@ template <class T> class MOS6522 {
timer_is_running_[0] = false;\
}
/*!
Runs for a specified number of half cycles.
/*! Runs for a specified number of half cycles. */
inline void run_for(const HalfCycles &half_cycles) {
int number_of_half_cycles = half_cycles.as_int();
Although the original chip accepts only a phase-2 input, timer reloads are specified as occuring
1.5 cycles after the timer hits zero. It therefore may be necessary to emulate at half-cycle precision.
The first emulated half-cycle will be the period between the trailing edge of a phase-2 input and the
next rising edge. So it should align with a full system's phase-1. The next emulated half-cycle will be
that which occurs during phase-2.
Callers should decide whether they are going to use @c run_for_half_cycles or @c run_for_cycles, and not
intermingle usage.
*/
inline void run_for_half_cycles(unsigned int number_of_cycles) {
if(is_phase2_) {
phase2();
number_of_cycles--;
number_of_half_cycles--;
}
while(number_of_cycles >= 2) {
while(number_of_half_cycles >= 2) {
phase1();
phase2();
number_of_cycles -= 2;
number_of_half_cycles -= 2;
}
if(number_of_cycles) {
if(number_of_half_cycles) {
phase1();
is_phase2_ = true;
} else {
@@ -283,13 +275,9 @@ template <class T> class MOS6522 {
}
}
/*!
Runs for a specified number of cycles.
Callers should decide whether they are going to use @c run_for_half_cycles or @c run_for_cycles, and not
intermingle usage.
*/
inline void run_for_cycles(unsigned int number_of_cycles) {
/*! Runs for a specified number of cycles. */
inline void run_for(const Cycles &cycles) {
int number_of_cycles = cycles.as_int();
while(number_of_cycles--) {
phase1();
phase2();