Difference between revisions of "Signals"

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*D0~D15: 68k data bus
 
*D0~D15: 68k data bus
 
*R/W: 68k Read/Write
 
*R/W: 68k Read/Write
*AS: 68k /AS
+
*AS: 68k Address Strobe
 +
*/DTACK: 68k Data Transmit ACKnowledge
 +
*/ROMWAIT: add 1-cycle delay for [[P ROM|P1 ROM]] reads
 +
*/PWAIT0, /PWAIT1: adds 0 to 3 cycle delay for [[P ROM|P2 ROM]] reads
 
*/ROMOEL: $000000-$0FFFFF ([[P ROM|P1 ROM]]) odd byte read
 
*/ROMOEL: $000000-$0FFFFF ([[P ROM|P1 ROM]]) odd byte read
 
*/ROMOEU: $000000-$0FFFFF (P1 ROM) even byte read
 
*/ROMOEU: $000000-$0FFFFF (P1 ROM) even byte read

Revision as of 03:43, 12 July 2012

  • 6M, 12M, 24M: 6MHz, 12MHz, and 24MHz clock signals
  • 4MB: 4MHz inverted signal
  • A1~A19: 68k address bus
  • D0~D15: 68k data bus
  • R/W: 68k Read/Write
  • AS: 68k Address Strobe
  • /DTACK: 68k Data Transmit ACKnowledge
  • /ROMWAIT: add 1-cycle delay for P1 ROM reads
  • /PWAIT0, /PWAIT1: adds 0 to 3 cycle delay for P2 ROM reads
  • /ROMOEL: $000000-$0FFFFF (P1 ROM) odd byte read
  • /ROMOEU: $000000-$0FFFFF (P1 ROM) even byte read
  • /ROMOE: $000000-$0FFFFF (P1 ROM) read
  • /PORTOEL: $200000-$2FFFFF (P2+ ROM/Security chip) odd byte read
  • /PORTOEU: $200000-$2FFFFF (P2+ ROM/Security chip) even byte read
  • /PORTWEL: $200000-$2FFFFF (P2+ ROM/Security chip) odd byte write
  • /PORTWEU: $200000-$2FFFFF (P2+ ROM/Security chip) even byte write
  • /PORTADRS: $200000-$2FFFFF (P2+ ROM/Security chip) any access
  • CR0~CR31: C ROMs data bus (2*16bits), holds data for one 8 pixels line
  • SDA0~SDA15 : Z80 address bus
  • SDD0~SDD7: Z80 data bus
  • SDRAD0~SDRAD7: ADPCM-A ROM multiplexed bus (data/address)
  • SDRA8,SDRA9,SDRA20~SDRA23: ADPCM-A ROM address bus
  • SDPAD0~SDPAD7: ADPCM-B ROM multiplexed bus (data/address)
  • SDPA8,SDPA9,SDPA10,SDPA11: ADPCM-B ROM address bus
  • P0~P23: C ROM, S ROM and LO ROM address/data bus (multiplexed)
  • PCK1B: Clock to latch C ROM address from P0~P23 (mapping) on rising edge
  • PCK2B: Clock to latch S ROM address from P0~P15 (mapping) on rising edge
  • CA4: C ROM A4
  • 2H1: S ROM A3
  • FIXD0~FIXD7: S ROM data bus