Project Peacock
From Hackstrich
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
- PIC32MX575F512H seems a good fit, and keeps commonality with another project (BIRD)
- 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
- SRAM
- Output converter
- TMDS converter for DVI
- DAC for VGA