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Beefs up documentation and developer support.

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This commit is contained in:
Thomas Harte 2019-04-19 13:29:35 -04:00
parent 9ef7743205
commit 2d97fc1f59
2 changed files with 36 additions and 3 deletions
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2
OSBindings/Mac/Clock SignalTests/EmuTOSTests.mm
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@ -121,7 +121,7 @@ class EmuTOS: public CPU::MC68000::BusHandler {
- (void)testStartup {
// This is an example of a functional test case.
// Use XCTAssert and related functions to verify your tests produce the correct results.
_machine->run_for(HalfCycles(400000));
_machine->run_for(HalfCycles(8000000));
}
@end

37
Processors/68000/68000.hpp
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@ -117,20 +117,53 @@ struct Microcycle {
}
/*!
Obtains the mask to apply to a word that will leave only the byte this microcycle is selecting.
@returns 0x00ff if this byte access wants the low part of a 16-bit word; 0xff00 if it wants the high part.
*/
inline unsigned int byte_mask() const {
return 0xff00 >> (((*address) & 1) << 3);
inline uint16_t byte_mask() const {
return uint16_t(0xff00) >> (((*address) & 1) << 3);
}
/*!
Obtains the mask to apply to a word that will leave only the byte this microcycle **isn't** selecting.
i.e. this is the part of a word that should be untouched by this microcycle.
@returns 0xff00 if this byte access wants the low part of a 16-bit word; 0x00ff if it wants the high part.
*/
inline uint16_t untouched_byte_mask() const {
return uint16_t(uint16_t(0xff) << (((*address) & 1) << 3));
}
/*!
Assuming this cycle is a byte write, mutates @c destination by writing the byte to the proper upper or
lower part, retaining the other half.
*/
uint16_t write_byte(uint16_t destination) const {
return uint16_t((destination & untouched_byte_mask()) | (value->halves.low << byte_shift()));
}
/*!
@returns non-zero if this is a byte read and 68000 LDS is asserted.
*/
inline int lower_data_select() const {
return (operation & SelectByte) & ((*address & 1) << 3);
}
/*!
@returns non-zero if this is a byte read and 68000 UDS is asserted.
*/
inline int upper_data_select() const {
return (operation & SelectByte) & ~((*address & 1) << 3);
}
/*!
@returns the address being accessed at the precision a 68000 supplies it —
only 24 address bit precision, with the low bit shifted out. So it's the
68000 address at word precision: address 0 is the first word in the address
space, address 1 is the second word (i.e. the third and fourth bytes) in
the address space, etc.
*/
uint32_t word_address() const {
return (address ? (*address) & 0x00fffffe : 0) >> 1;
}