AMD SC1200, SC1201 manual Fast-PCI Bus, Display, 1 GX1 Module Interface, Video Input Port, Crt Dac

32579B Architecture Overview

2.1.2Fast-PCI Bus

The GX1 module communicates with the Core Logic mod- ule via a Fast-PCI bus that can work at up to 66 MHz. The Fast-PCI bus is internal for the SC1200/SC1201 processor and is connected to the General Configuration Block (see Section 4.0 on page 71 for details on the General Configu- ration Block).

This bus supports seven bus masters. The requests (REQs) are fixed in priority. The seven bus masters in order of priority are:

1)VIP

2)IDE Channel 0

3)IDE Channel 1

4)Audio

5)USB

6)External REQ0#

7)External REQ1#

2.1.3Display

The GX1 module generates display timing, and controls internal signals CRT_VSYNC and CRT_HSYNC of the Video Processor module.

The GX1 module interfaces with the Video Processor via a video data bus and a graphics data bus.

•Video data. The GX1 module uses the core clock, divided by 2 or 4 (typically 100 to 133 MHz). It drives the video data using this clock. Internal signals VID_VAL and VID_RDY are used as data-flow handshake signals between the GX1 module and the Video Processor.

•Graphics data. The GX1 module uses the internal DCLK signal, supplied by the PLL of the Video Processor, to drive the 18-bit graphics-data bus of the Video Processor. Each six bits of this bus define a different color. Each of these 6-bit color definitions is expanded (by adding two zero LSB lines) to form an 8-bit bus, at the Video Processor.

For more information about the GX1 module’s interface to the Video Processor, see the “Display Controller” chapter in the AMD Geode™ GX1 Processor Data Book.

2.2Video Processor Module

The Video Processor provides high resolution and graphics for a CRT, TV, or TFT/DSTN interface. The following sub- sections provide a summary of how the Video Processor interfaces with the other modules of the SC1200/SC1201 processor. For detailed information about the Video Pro- cessor, see Section 7.0 on page 311.

2.2.1GX1 Module Interface

The Video Processor is connected to the GX1 module in the following way:

•The Video Processor’s DOTCLK output signal is used as the GX1 module’s DCLK input signal.

•The GX1 module’s PCLK output signal is used as the GFXCLK input signal of the Video Processor.

2.2.2Video Input Port

The Video Input Port (VIP) within the Video Processor con- tains a standard interface that is typically connected to a media processor or TV encoder. The clock is supplied by the externally connected device; typically at 27 MHz.

Video input can be sent to the GX1 module’s video frame buffer (Capture Video mode) or can be used directly (Direct Video mode).

2.2.3Core Logic Module Interface

The Video Processor interfaces to the Core Logic module for accessing PCI function configuration registers.

2.2.4CRT DAC

The Video Processor drives three CRT DACs with up to 135M pixels per second.

The interface for these DACs can be monitored via external balls of the SC1200/SC1201 processor. For more informa- tion, see Section 3.4.4 "CRT/TFT Interface Signals" on page 52.

2.3Core Logic Module

The Core Logic module is described in detail in Section 6.0 on page 141.

The Core Logic module is connected to the Fast-PCI bus. It uses signal AD28 as the IDSEL for all PCI configuration functions except for USB which uses AD29.

2.3.1Other Core Logic Module Interfaces

The following interfaces of the Core Logic module are implemented via external signals of the SC1200/SC1201 processor. Each interface is listed below with a reference to the descriptions of the relevant signals.

•IDE: See Section 3.4.10 "IDE Interface Signals" on page 61.

•AC97: See Section 3.4.15 "AC97 Audio Interface Signals" on page 65.

•PCI: See Section 3.4.7 "PCI Bus Interface Signals" on page 55.

22 AMD Geode™ SC1200/SC1201 Processor Data Book