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Extends list of BusOperations.

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Now to retest, widely.
This commit is contained in:
Thomas Harte 2020-10-15 21:35:01 -04:00
parent 9c0c0255f6
commit 5dcf720bb5
2 changed files with 37 additions and 8 deletions
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2
Machines/Atari/2600/Cartridges/Cartridge.hpp
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@ -75,7 +75,7 @@ template<class T> class Cartridge:
cycles_since_6532_update_ += Cycles(cycles_run_for / 3);
bus_extender_.advance_cycles(cycles_run_for / 3);
if(operation != CPU::MOS6502::BusOperation::Ready) {
if(isAccessOperation(operation)) {
// give the cartridge a chance to respond to the bus access
bus_extender_.perform_bus_operation(operation, address, value);

43
Processors/6502Esque/6502Esque.hpp
View File

@ -36,7 +36,7 @@ enum Register {
X,
Y,
// These exist on the 65816 only.
// These exist on a 65816 only.
EmulationFlag,
DataBank,
ProgramBank,
@ -64,24 +64,53 @@ enum Flag: uint8_t {
/*!
Bus handlers will be given the task of performing bus operations, allowing them to provide whatever interface they like
between a 6502 and the rest of the system. @c BusOperation lists the types of bus operation that may be requested.
@c None is reserved for internal use. It will never be requested from a subclass. It is safe always to use the
isReadOperation macro to make a binary choice between reading and writing.
between a 6502-esque chip and the rest of the system. @c BusOperation lists the types of bus operation that may be requested.
*/
enum BusOperation {
/// 6502: indicates that a read was signalled.
/// 65816: indicates that a read was signalled with VDA.
Read,
/// 6502: indicates that a read was signalled with SYNC.
/// 65816: indicates that a read was signalled with VDA and VPA.
ReadOpcode,
/// 6502: never signalled.
/// 65816: indicates that a read was signalled with VPA.
ReadProgram,
/// 6502: never signalled.
/// 65816: indicates that a read was signalled with VPB.
ReadVector,
/// 6502: indicates that a write was signalled.
/// 65816: indicates that a write was signalled with VDA.
Write,
/// All processors: indicates that the processor is holding state due to the RDY input.
/// 65C02 and 65816: indicates a WAI is ongoing.
Ready,
None
/// 6502: never signalled.
/// 65816: indicates that a read was signalled, but neither VDA or VPA were active.
InternalOperation,
/// 65C02 and 65816: indicates a STP condition.
None,
};
/*!
Evaluates to `true` if the operation is a read; `false` if it is a write or ready.
Evaluates to @c true if the operation is any sort of read; @c false otherwise.
*/
#define isReadOperation(v) (v < CPU::MOS6502Esque::BusOperation::Write)
/*!
Evaluates to @c true if the operation is any sort of write; @c false otherwise.
*/
#define isWriteOperation(v) (v == CPU::MOS6502Esque::BusOperation::Write)
/*!
Evaluates to @c true if the operation is any sort of memory access; @c false otherwise.
*/
#define isAccessOperation(v) (v < CPU::MOS6502Esque::BusOperation::Ready)
/*!
A class providing empty implementations of the methods a 6502 uses to access the bus. To wire the 6502 to a bus,
machines should subclass BusHandler and then declare a realisation of the 6502 template, suplying their bus