LSPC2-A2: Difference between revisions

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*68k VRAM access arbitration
*68k VRAM access arbitration


{{Chipname|LSPC-A0}} chips can be found on early MVS slots and AES systems and work alongside the {{Chipname|PRO-B0}} chip.
First generation {{Chipname|LSPC-A0}} chips can be found in earlier systems.


=Graphics=
=Graphics=
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Two separate busses run in parallel to fetch data from the two VRAM zones. Each bus connects to a pair of 8-bit RAM chips.
Two separate busses run in parallel to fetch data from the two VRAM zones. Each bus connects to a pair of 8-bit RAM chips.


*VRAM $0000~$7FFF - 2x 62256/43256 (120ns(?) or faster)
*VRAM $0000~$7FFF - 2x 62256/43256
*VRAM $8000~$87FF - 2x 5814/5863/6116 (45ns or faster)
*VRAM $8000~$87FF - 2x 5814/5863/6116


The LSPC arbitrates all VRAM access and allows for {{Chipname|68k}} access at (almost) any time during rendering without display glitches. The interface is slow and some access can be ignored when too fast, especially with [[overclocking|overclocked]] systems.
The LSPC arbitrates all VRAM access and allows for {{Chipname|68k}} access at any time during rendering without display glitches if they aren't made too fast. See [[VRAM]] for timing requirements.


It shares a 24-bit [[P bus]] (P0~P23) with NEO-B1 and the on-board L0 ROM, which goes out to the [[Pinouts#Cartridges|CHA connector]] on the cart slot for addressing {{Chipname|S ROM}}s and {{Chipname|C ROM}}s.
It shares the 24-bit [[P bus]] (P0~P23) with NEO-B1 and the on-board [[L0 ROM]], which goes out to the [[Pinouts#Cartridges|CHA connector]] on the cart slot for addressing {{Chipname|S ROM}}s and {{Chipname|C ROM}}s.


=IRQs=
=IRQs=


All 3 (2 ?) [[68k interrupts]] are generated by this chip.
All 3 possible [[68k interrupts]] are generated by this chip.


=Pinout=
=Pinout=
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OpenOffice Draw file: [[File:lspc2-a2.odg]]
OpenOffice Draw file: [[File:lspc2-a2.odg]]
Need to find: 28,87,128,133


*A1~A3: 68k address bus
*A1~A3: 68k address bus
*D0~D15: 68k data bus
*D0~D15: 68k data bus
*/LSPOE,/LSPWE: Chip read/write, provided by {{Chipname|NEO-C1}}
*B0~B14: VRAM bank 0 address bus
*B0~B14: VRAM bank 0 address bus
*E0~E15: VRAM bank 0 data bus
*E0~E15: VRAM bank 0 data bus
*/BOE,/BWE: VRAM bank 0 read/write
*C0~C10: VRAM bank 1 address bus
*C0~C10: VRAM bank 1 address bus
*/CWE: VRAM bank 1 write enable
*F0~F15: VRAM bank 1 data bus
*F0~F15: VRAM bank 1 data bus
*P0~P23: "Internal" multiplexed P bus
*P0~P23: Multiplexed P bus
*/BOE,/BWE: VRAM bank 0 read/write
*/CWE: VRAM bank 1 write enable
*/LSPOE,/LSPWE: Chip read/write, provided by {{Chipname|NEO-C1}}
*/RES: Reset
*/RES: Reset
*1H1:
*1H1: Clock used by NEO-B1
*2H1: S ROM A3
*2H1: S ROM A3
*24M: 24MHz clock input from {{Chipname|NEO-D0}}
*24M: 24MHz clock input from {{Chipname|NEO-D0}}
*4M: 4MHz clock output to {{Chipname|Z80}}
*8M: 8MHz clock output to the {{Chipname|YM2610}}
*6M: 6MHz clock output to the cartridge connector
*4M: 4MHz clock output to the {{Chipname|Z80}}
*CA4: C ROM A4
*CA4: C ROM A4
*DIVI/DIVO: Frequency divider ?
*DIVI/DIVO/REF: Independant frequency division circuit used by the [[video PLL]]
*EVEN1, EVEN2, H, LOAD: C ROM multiplexer control, see {{Chipname|NEO-ZMC2}}
*EVEN1, EVEN2, H, LOAD: C ROM serializer control, see {{Chipname|NEO-ZMC2}}
*DOTA/DOTB: Transparency input from NEO-ZMC2
*DOTA/DOTB: Pixel opacity inputs from NEO-ZMC2
*INT:
*IP0/IP1: 68k interrupt lines
*IP0/IP1: 68k interrupt level
*PK1: Clock to latch C ROM address from P bus
*PK1: Clock to latch C ROM address from P bus
*PK2: Clock to latch S ROM address from P bus
*PK2: Clock to latch S ROM address from P bus
*REF:
*RESETP: Reset pulse output
*RESETF:
*6MB: Pixel clock output
*SCH?:
*SYNC: Video sync signal output
*SL1?/SL2?:
*TST: Enable test mode, uses D0~D10 (always tied to ground)
*6M: 6MHz clock output to {{Chipname|YM2610}} and cartridge connector
*VCS: L0 ROM output enable
*6MB: Pixel clock
*SYNC: Video sync signal
*TST:
*TST0:
*VCS:
*WE1~WE4: Synchronous write enable signals for NEO-B1
*WE1~WE4: Synchronous write enable signals for NEO-B1
*CK1~CK4: Clocks for rendering in, and output from NEO-B1
*CK1~CK4: Clocks for rendering and output from NEO-B1
*SS1, SS2: NEO-B1 control, can't remember what they do. Line buffer switch ?
*SS1, SS2: NEO-B1 control
*BNKB: Video blanking (for V-blank)
*BNKB: Video blanking (for V-blank)
*CHBL: Video blanking (for H-blank, sent to NEO-B1)
*CHBL: Video blanking (for H-blank, sent to NEO-B1)
*PAL/NTSC: Video mode selection, latched during reset


[[Category:Chips]]
[[Category:Chips]]

Revision as of 23:38, 7 February 2018

Package QFP176
Manufacturer
First use 1992 ?
Used on NEO-AES3-4 MV1F

MV1FZ...

LSPC2-A2 is the second generation Line SPrite Controller, it is only found in cartridge systems.

  • Generates S ROM, C ROM and LO ROM addresses based on current display line and VRAM content
  • Sync output
  • NEO-B1 control
  • 68k IRQs
  • 68k VRAM access arbitration

First generation LSPC-A0 chips can be found in earlier systems.

Graphics

Two separate busses run in parallel to fetch data from the two VRAM zones. Each bus connects to a pair of 8-bit RAM chips.

  • VRAM $0000~$7FFF - 2x 62256/43256
  • VRAM $8000~$87FF - 2x 5814/5863/6116

The LSPC arbitrates all VRAM access and allows for 68k access at any time during rendering without display glitches if they aren't made too fast. See VRAM for timing requirements.

It shares the 24-bit P bus (P0~P23) with NEO-B1 and the on-board L0 ROM, which goes out to the CHA connector on the cart slot for addressing S ROMs and C ROMs.

IRQs

All 3 possible 68k interrupts are generated by this chip.

Pinout

(Max size:File:lspc2-a2_pinout.png)
File:Lspc2-a2 pinout.png

OpenOffice Draw file: File:Lspc2-a2.odg

  • A1~A3: 68k address bus
  • D0~D15: 68k data bus
  • /LSPOE,/LSPWE: Chip read/write, provided by NEO-C1
  • B0~B14: VRAM bank 0 address bus
  • E0~E15: VRAM bank 0 data bus
  • /BOE,/BWE: VRAM bank 0 read/write
  • C0~C10: VRAM bank 1 address bus
  • /CWE: VRAM bank 1 write enable
  • F0~F15: VRAM bank 1 data bus
  • P0~P23: Multiplexed P bus
  • /RES: Reset
  • 1H1: Clock used by NEO-B1
  • 2H1: S ROM A3
  • 24M: 24MHz clock input from NEO-D0
  • 8M: 8MHz clock output to the YM2610
  • 6M: 6MHz clock output to the cartridge connector
  • 4M: 4MHz clock output to the Z80
  • CA4: C ROM A4
  • DIVI/DIVO/REF: Independant frequency division circuit used by the video PLL
  • EVEN1, EVEN2, H, LOAD: C ROM serializer control, see NEO-ZMC2
  • DOTA/DOTB: Pixel opacity inputs from NEO-ZMC2
  • IP0/IP1: 68k interrupt lines
  • PK1: Clock to latch C ROM address from P bus
  • PK2: Clock to latch S ROM address from P bus
  • RESETP: Reset pulse output
  • 6MB: Pixel clock output
  • SYNC: Video sync signal output
  • TST: Enable test mode, uses D0~D10 (always tied to ground)
  • VCS: L0 ROM output enable
  • WE1~WE4: Synchronous write enable signals for NEO-B1
  • CK1~CK4: Clocks for rendering and output from NEO-B1
  • SS1, SS2: NEO-B1 control
  • BNKB: Video blanking (for V-blank)
  • CHBL: Video blanking (for H-blank, sent to NEO-B1)
  • PAL/NTSC: Video mode selection, latched during reset
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