Fastwel CPB904, User Manual, Page: 23 / 31

Functional Description CPB904
4.2.4 DMA Channels
Table 4.4: DMA Request Map
DMA Channel Main Function Alternative Source
0 Reserved –
1 LPT DRQ1 line of external ISA bus
2 FDD –
3 DRQ3 line of external ISA bus –
4 Slave controller –
5 – –
6 – –
7 – –
4.3 Functional Description
4.3.1 Microprocessor
The module is based on AMD Geode LX800 microprocessor with 1.8W typical power consumption
at 500 MHz, maximum power 3.6W (TDP). The processor includes 32-bit x86 core, 64-bit
coprocessor and 64-bit DDR memory bus up to 400 MHz, graphics and video controller with VGA
monitors and LCD panels simultaneous operation support. FPU of the processor supports MMX™
and AMD 3DNow!™ technology instruction sets. The CPU is complemented with AMD Geode
CS5536 companion device providing support for numerous I/O functions including IDE, USB,
audio, and power management interfaces.
4.3.2 SDRAM Memory
Four DDR 333 SDRAM memory chips are soldered on the bottom side of the PCB. Total memory
size is 256 or 512 MB depending on the version of the module. In addition, the module can accept
up to 512 MB of DDR SDRAM via SODIMM socket on the top side of the board (for CPB904-03).
4.3.3 PCI and ISA Buses
Expansion capabilities of CPB904 are supported by 32-bit PCI bus routed to X1 ETX connector.
Moreover, ITE IT8888G PCI-to-ISA bridge provides full-functional 16-bit ISA bus available via X2
ETX connector.
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