A slightly revised HuC6280A was released and used in the PC Engine CoreGrafx and SuperGrafx. This revision reportedly fixed some minor audio issues in those systems.
Memory mappingedit
The HuC6280 has a 64 KB logical address space, but a 2 MB physical address space. The HuC6280 uses a Memory Management Unit that splits the memory space into segments of 8 KB. Each logical 8 KB segment is associated with one of 256 physical 8 KB sized segments. This can be set up with an 8-bit register (MPR0-7) that contains the most significant eight bits of the address of the 8 KB segment in physical memory. Thus the logical 64 KB address space can be overlapping, continuous or scattered in physical address space, depending on the eight MPR registers.
Two special instructions are used to access these registers:
TAMi - transfer the content of the accumulator (A) into an MPR register (0-7).
TMAi - transfer an MPR register into the accumulator.
Sound generatoredit
PSG-styled wavetable synthesis provides six sound channels, which can be conveniently paired according to the functionality they provide:
0-1 - Waveform playback Frequency modulation (channel 1 muted) 2-3 - Waveform playback only 4-5 - Waveform playback White noise generation
Waveform playback is the most common and allows a 32-byte, 5-bit unsigned linear sample to be played back at selected frequencies. Frequency modulation takes this one step further, allowing the playback frequency to be dynamically adjusted according to a specified pattern. White noise is used to simulate percussion instruments and effects, such as explosions, by means of a pseudo-random square wave.
Alternatively, each channel can be individually switched to "Direct D/A" mode in which the programmer can send data directly to the sound mixer, allowing more complex sound patterns to be generated, such as speech. Inevitably, this requires more programming effort and CPU time.
hudson, soft, huc6280, this, article, does, cite, sources, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, august, 2014, learn, when, . This article does not cite any sources Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Hudson Soft HuC6280 news newspapers books scholar JSTOR August 2014 Learn how and when to remove this template message The HuC6280 8 bit microprocessor is Japanese company Hudson Soft s improved version of the WDC 65C02 CPU an upgraded CMOS version of the popular NMOS based MOS Technology 6502 8 bit CPU manufactured for Hudson by Seiko Epson and NEC The most notable product using the HuC6280 is NEC s TurboGrafx 16 video game console Revised HuC6280A Contents 1 Description 2 Memory mapping 3 Sound generator 4 External linksDescription editThe HuC6280 contains a 65C02 core which has several additional instructions and a few internal peripheral functions such as an interrupt controller a memory management unit a timer an 8 bit parallel I O port and a programmable sound generator PSG The processor operates at two speeds 1 79 MHz and 7 16 MHz A slightly revised HuC6280A was released and used in the PC Engine CoreGrafx and SuperGrafx This revision reportedly fixed some minor audio issues in those systems Memory mapping editThe HuC6280 has a 64 KB logical address space but a 2 MB physical address space The HuC6280 uses a Memory Management Unit that splits the memory space into segments of 8 KB Each logical 8 KB segment is associated with one of 256 physical 8 KB sized segments This can be set up with an 8 bit register MPR0 7 that contains the most significant eight bits of the address of the 8 KB segment in physical memory Thus the logical 64 KB address space can be overlapping continuous or scattered in physical address space depending on the eight MPR registers Two special instructions are used to access these registers TAMi transfer the content of the accumulator A into an MPR register 0 7 TMAi transfer an MPR register into the accumulator Sound generator editPSG styled wavetable synthesis provides six sound channels which can be conveniently paired according to the functionality they provide 0 1 Waveform playback Frequency modulation channel 1 muted 2 3 Waveform playback only 4 5 Waveform playback White noise generation Waveform playback is the most common and allows a 32 byte 5 bit unsigned linear sample to be played back at selected frequencies Frequency modulation takes this one step further allowing the playback frequency to be dynamically adjusted according to a specified pattern White noise is used to simulate percussion instruments and effects such as explosions by means of a pseudo random square wave Alternatively each channel can be individually switched to Direct D A mode in which the programmer can send data directly to the sound mixer allowing more complex sound patterns to be generated such as speech Inevitably this requires more programming effort and CPU time External links edithttp shu emuunlim com download pcedocs pce cpu html http www magicengine com mkit http www interlog com daves pce info info html https www copetti org writings consoles pc engine Retrieved from https en wikipedia org w index php title Hudson Soft HuC6280 amp oldid 1217241461, wikipedia, wiki, book, books, library,
