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Alpha board connectors, for safe keeping:

(PCB IDs are those of the Model B Alpha board)

  • SoC: Broadcom BCM2835 media processor system-on-chip featuring:
    • CPU core: ARM1176JZF-S ARM11 core clocked at 700MHz; ARM VFP.
    • GPU core: a Broadcom VideoCore GPU providing OpenGL ES 1.1, OpenGL ES 2.0, hardware-accelerated OpenVG 1.1, Open EGL, OpenMAX and 1080p30 H.264 high-profile decode. There are 24 GFLOPS of general purpose compute and a bunch of texture filtering and DMA infrastructure. Eben worked on the architecture team for this and the Raspberry Pi team are looking at how they can make some of the proprietary features available to application programmers
    • DSP core: There is a DSP, but there isn't currently a public API (Liz thinks the BC team are keen to make one available at some point)
    • RAM: 128MiB (Model A) or 256MiB (Model B) of SDRAM. The RAM is physically stacked on top of the Broadcom media processor (package-on-package technology)
  • J1: DC Jack (6-20v input provisionally)
  • J2: 4-pin UART serial console (debug)
  • J3: SD/MMC/SDIO memory card slot (underside)
  • J4: HDMI connector providing HDMI 1.3a out
  • J5 or J9: 6-pin GPU JTAG (ARM11 pinout; no-fit on production boards)
  • J6: Audio connector: 3.5mm stereo jack
  • J7: Composite Video connector: RCA
  • J8: Either 1x USB 2.0 (Model A) or LAN9512 (Data Brief | Data Sheet) providing 10/100Mb Ethernet and 2x USB 2.0 (J10: Model B)
  • J10: 10/100Mb RJ45 Ethernet jack
  • J11, J14: 26-pin 1.27mm headers providing ~16 GPIOs at 3v3, I2C, I2S and SPI interfaces and ARM JTAG.
  • J12: 12-pin 1.27mm header providing DSI interface
  • J13: 12-pin 1.27mm header providing MIPI CSI-2 interface

Alpha board UART

J2 (on the alpha boards) is a UART:

Pin Function
1 3.3V
3 TX
4 RX

Kernel boot messages go to this UART at 115200bps.

On the production boards, UART has been moved to the GPIO header


On the Alpha board, we also bring out MIPI CSI-2 & DSI interfaces to a 1.27 mm pinstrip.


Why are the references broken?

Interfacing to Raw LCD Panels

It would be great if someone could expand on this section; to cover what exactly is required to connect the board's DSI interface to an LCD.

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