Difference between revisions of "Project Peacock"

From Hackstrich
(I/O pin estimates)
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* Display Controller MCU
 
* Display Controller MCU
 
** Communicate with host via I2C/SPI/RS232
 
** Communicate with host via I2C/SPI/RS232
 +
** Will need a lot of I/O pins
 +
*** RAM address bus - 22 pins
 +
*** RAM data bus - 16 pins
 +
*** RAM arbitration/handshaking - 6 pins
 +
*** SPI/I2C/RS232 - 4 pins
 +
*** '''Rough total - 48 I/O pins required'''
 
* Display Driver CPLD
 
* Display Driver CPLD
 
** Essentially just the digital part of a RAMDAC, constantly reads data from the RAM and spits it out to the output converter
 
** Essentially just the digital part of a RAMDAC, constantly reads data from the RAM and spits it out to the output converter
 +
** Since it's dealing with RAM anyway, it can handle the RAM details for the MCU (accept raw data from the MCU and write it to memory)
 
** Using a CPLD means the Display Controller MCU doesn't need to be super-fast
 
** Using a CPLD means the Display Controller MCU doesn't need to be super-fast
 
* RAM
 
* RAM

Revision as of 01:39, 11 September 2010

Project Peacock will be (in theory) a chipset for doing DVI/VGA display output from a microcontroller. It will consist of:

  • Display Controller MCU
    • Communicate with host via I2C/SPI/RS232
    • Will need a lot of I/O pins
      • RAM address bus - 22 pins
      • RAM data bus - 16 pins
      • RAM arbitration/handshaking - 6 pins
      • SPI/I2C/RS232 - 4 pins
      • Rough total - 48 I/O pins required
  • Display Driver CPLD
    • Essentially just the digital part of a RAMDAC, constantly reads data from the RAM and spits it out to the output converter
    • Since it's dealing with RAM anyway, it can handle the RAM details for the MCU (accept raw data from the MCU and write it to memory)
    • Using a CPLD means the Display Controller MCU doesn't need to be super-fast
  • RAM
    • SRAM
      • Far too expensive (~$200) for the amount needed
    • PSRAM (Pseudo SRAM)/CellularRAM
      • SRAM interface but DRAM backend, simple to interface with and cheap (~$6)
      • Only available in VFBGA package meaning a four-layer board would be required, and hard to solder
    • SDRAM
      • Inexpensive (~$5) and readily available
      • Easy non-BGA SMT packages
      • Harder to interface with, would need to have the CPLD handle RAM refreshing and other housekeeping
  • Output converter
    • TMDS converter for DVI
    • DAC for VGA