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Improve commentary.

This commit is contained in:
Thomas Harte 2020-10-19 09:32:50 -04:00 committed by GitHub
parent 69450e27ad
commit 14718b93a4
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@ -192,7 +192,7 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
// 1b. Absolute; a, JMP.
static void absolute_jmp(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // New PCL.]
target(CycleFetchIncrementPC); // New PCL.
target(CycleFetchPC); // New PCH.
target(OperationPerform); // [JMP]
}
@ -201,10 +201,10 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
static void absolute_jsr(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // New PCL.
target(CycleFetchPC); // New PCH.
target(CycleFetchPCThrowaway); // IO
target(OperationPerform); // [JSR]
target(CyclePush); // PCH
target(CyclePush); // PCL
target(CycleFetchPCThrowaway); // IO.
target(OperationPerform); // [JSR].
target(CyclePush); // PCH.
target(CyclePush); // PCL.
}
// 1d. Absolute; a, read-modify-write.
@ -232,8 +232,8 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(CycleFetchIncrementPC); // AAL.
target(OperationCopyPCToData); // Prepare to push.
target(CyclePush); // PCH
target(CyclePush); // PCL
target(CyclePush); // PCH.
target(CyclePush); // PCL.
target(CycleFetchPC); // AAH.
target(CycleFetchPCThrowaway); // IO.
@ -250,9 +250,9 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(CycleFetchPC); // New AAH.
target(OperationConstructAbsolute16); // Calculate data address.
target(CycleFetchIncrementData); // New PCL
target(CycleFetchIncrementData); // New PCH
target(CycleFetchData); // New PBR
target(CycleFetchIncrementData); // New PCL.
target(CycleFetchIncrementData); // New PCH.
target(CycleFetchData); // New PBR.
target(OperationPerform); // [JML]
}
@ -263,8 +263,8 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(CycleFetchPC); // New AAH.
target(OperationConstructAbsolute16); // Calculate data address.
target(CycleFetchIncrementData); // New PCL
target(CycleFetchData); // New PCH
target(CycleFetchIncrementData); // New PCL.
target(CycleFetchData); // New PCH.
target(OperationPerform); // [JMP]
}
@ -303,8 +303,8 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(OperationConstructAbsolute); // Calculate data address.
target(OperationPerform); // [JSL]
target(CyclePush); // PCH
target(CyclePush); // PCL
target(CyclePush); // PCH.
target(CyclePush); // PCL.
}
// 5. Absolute long, X; al, x.
@ -328,7 +328,7 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
} else {
target(OperationConstructAbsoluteX); // Calculate data address.
}
target(CycleFetchIncorrectDataAddress); // Do the dummy read if necessary; OperationConstructAbsoluteX
target(CycleFetchIncorrectDataAddress); // Do the dummy read if necessary; OperationConstructAbsoluteXRead
// will skip this if it isn't required.
read_write(type, is8bit, target);
@ -355,7 +355,7 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
} else {
target(OperationConstructAbsoluteY); // Calculate data address.
}
target(CycleFetchIncorrectDataAddress); // Do the dummy read if necessary; OperationConstructAbsoluteX
target(CycleFetchIncorrectDataAddress); // Do the dummy read if necessary; OperationConstructAbsoluteYRead
// will skip this if it isn't required.
read_write(type, is8bit, target);
@ -420,8 +420,8 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchIncrementData); // AAL
target(CycleFetchData); // AAH
target(CycleFetchIncrementData); // AAL.
target(CycleFetchData); // AAH.
target(OperationCopyDataToInstruction);
target(OperationConstructAbsolute);
@ -545,14 +545,14 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
// 19a. Implied; i.
static void implied(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(OperationPerform);
}
// 19b. Implied; i; XBA.
static void implied_xba(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
target(OperationPerform);
}
@ -560,24 +560,25 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
// 19d. Wait for interrupt.
static void stp_wai(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(OperationPerform); // Establishes the termination condition.
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
target(CycleRepeatingNone); // This will first check whether the STP/WAI exit
// condition has occurred; if not then it'll issue
// a BusOperation::None and then reschedule itself.
// either a BusOperation::None or ::Ready and then
// reschedule itself.
}
// 20. Relative; r.
static void relative(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // Offset
target(CycleFetchIncrementPC); // Offset.
target(OperationPerform); // The branch instructions will all skip one or three
// of the next cycles, depending on the effect of
// the jump. It'll also calculate the correct target
// address, placing it into the data buffer.
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
target(OperationCopyDataToPC); // Install the address that was calculated above.
}
@ -586,34 +587,34 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
static void relative_long(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // Offset low.
target(CycleFetchIncrementPC); // Offset high.
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(OperationPerform); // [BRL]
}
// 22a. Stack; s, abort/irq/nmi/res.
static void stack_exception(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
target(OperationPrepareException); // Populates the data buffer; this skips a micro-op if
// in emulation mode.
target(CyclePush); // PBR [skipped in emulation mode]
target(CyclePush); // PCH
target(CyclePush); // PCL
target(CyclePush); // P
target(CyclePush); // PBR [skipped in emulation mode].
target(CyclePush); // PCH.
target(CyclePush); // PCL.
target(CyclePush); // P.
target(CycleFetchIncrementVector); // AAVL
target(CycleFetchVector); // AAVH
target(CycleFetchIncrementVector); // AAVL.
target(CycleFetchVector); // AAVH.
target(OperationPerform); // Jumps to the vector address.
}
// 22b. Stack; s, PLx.
static void stack_pull(AccessType, bool is8bit, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
if(!is8bit) target(CyclePull); // REG low.
target(CyclePull); // REG [high].
@ -623,7 +624,7 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
// 22c. Stack; s, PHx.
static void stack_push(AccessType, bool is8bit, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(OperationPerform);
@ -633,70 +634,70 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
// 22d. Stack; s, PEA.
static void stack_pea(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // AAL
target(CycleFetchIncrementPC); // AAH
target(CyclePush); // AAH
target(CyclePush); // AAL
target(CycleFetchIncrementPC); // AAL.
target(CycleFetchIncrementPC); // AAH.
target(CyclePush); // AAH.
target(CyclePush); // AAL.
}
// 22e. Stack; s, PEI.
static void stack_pei(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // DO
target(CycleFetchIncrementPC); // DO.
target(OperationConstructDirect);
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchIncrementData); // AAL
target(CycleFetchData); // AAH
target(CyclePush); // AAH
target(CyclePush); // AAL
target(CycleFetchIncrementData); // AAL.
target(CycleFetchData); // AAH.
target(CyclePush); // AAH.
target(CyclePush); // AAL.
}
// 22f. Stack; s, PER.
static void stack_per(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // Offset low.
target(CycleFetchIncrementPC); // Offset high.
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(OperationConstructPER);
target(CyclePush); // AAH
target(CyclePush); // AAL
target(CyclePush); // AAH.
target(CyclePush); // AAL.
}
// 22g. Stack; s, RTI.
static void stack_rti(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
target(CyclePull); // P
target(CyclePull); // New PCL
target(CyclePull); // New PCH
target(CyclePullIfNotEmulation); // PBR
target(CyclePull); // P.
target(CyclePull); // New PCL.
target(CyclePull); // New PCH.
target(CyclePullIfNotEmulation); // PBR.
target(OperationPerform); // [RTI] — to unpack the fields above.
}
// 22h. Stack; s, RTS.
static void stack_rts(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchPCThrowaway); // IO.
target(CycleFetchPCThrowaway); // IO.
target(CyclePull); // PCL
target(CyclePull); // PCH
target(CycleAccessStack); // IO
target(CyclePull); // PCL.
target(CyclePull); // PCH.
target(CycleAccessStack); // IO.
target(OperationPerform); // [RTS]
}
// 22i. Stack; s, RTL.
static void stack_rtl(AccessType, bool, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // IO
target(CycleFetchIncrementPC); // IO
target(CycleFetchIncrementPC); // IO.
target(CycleFetchIncrementPC); // IO.
target(CyclePull); // New PCL
target(CyclePull); // New PCH
target(CyclePull); // New PBR
target(CyclePull); // New PCL.
target(CyclePull); // New PCH.
target(CyclePull); // New PBR.
target(OperationPerform); // [JML, to perform the RTL]
}
@ -708,21 +709,21 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(OperationPrepareException); // Populates the data buffer; this skips a micro-op if
// in emulation mode.
target(CyclePush); // PBR [skipped in emulation mode]
target(CyclePush); // PCH
target(CyclePush); // PCL
target(CyclePush); // P
target(CyclePush); // PBR [skipped in emulation mode].
target(CyclePush); // PCH.
target(CyclePush); // PCL.
target(CyclePush); // P.
target(CycleFetchIncrementVector); // AAVL
target(CycleFetchVector); // AAVH
target(CycleFetchIncrementVector); // AAVL.
target(CycleFetchVector); // AAVH.
target(OperationPerform); // Jumps to the vector address.
}
// 23. Stack Relative; d, s.
static void stack_relative(AccessType type, bool is8bit, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // SO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchIncrementPC); // SO.
target(CycleFetchPCThrowaway); // IO.
target(OperationConstructStackRelative);
read_write(type, is8bit, target);
@ -730,12 +731,12 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
// 24. Stack Relative Indirect Indexed (d, s), y.
static void stack_relative_indexed_indirect(AccessType type, bool is8bit, const std::function<void(MicroOp)> &target) {
target(CycleFetchIncrementPC); // SO
target(CycleFetchPCThrowaway); // IO
target(CycleFetchIncrementPC); // SO.
target(CycleFetchPCThrowaway); // IO.
target(OperationConstructStackRelative);
target(CycleFetchIncrementData); // AAL
target(CycleFetchData); // AAH
target(CycleFetchIncrementData); // AAL.
target(CycleFetchData); // AAH.
target(CycleFetchDataThrowaway); // IO.
target(OperationConstructStackRelativeIndexedIndirect);