User`s manual
AIMB-220 
18 AIMB-220 User’s Manual 
The Geode CS5536 companion device incorporates many I/O functions, including some 
found in typical superI/O chips, simplifying many system designs. Since the graphics 
subsystem is entirely contained in the Geode GX3 processor, system interconnect is 
simplified. The device contains state-of-the-art power management that enables systems, 
especially battery powered systems, to significantly reduce power consumption. 
Audio is supported by an internal controller, designed to connect to multiple AC97 
compatible codecs. An IR (infrared) port supports all popular IR communication protocols. 
The IR port is shared with one of two industry-standard serial ports that can reach speeds 
of 115.2 kbps. An LPC (low pin count) port is provided to facilitate connections to a 
superI/O should additional expansion, such as a floppy drive, be necessary, and/or to an 
LPC ROM for the system BIOS. 
The hard disk controller is compatible to the ATA-6 specification. The bus mastering IDE 
controller includes support for two ATA-compliant devices on one channel. The CS5536 
companion device provides four Universal Serial Bus (USB) 2.0 compliant ports, supporting 
low speed, full speed, and high speed connections. All four ports are individually 
automatically associated with either the Open Host Controller Interface (OHCI) or the 
Enhanced Host Controller Interface (EHCI) depending on the attached device type. A 
battery-backed real-time clock (RTC) keeps track of time and provides calendar functions. 
A suite of 82xx devices provides the legacy PC functionality required by most designs, 
including two PICs (programmable interrupt controllers), one PIT (programmable interval 
timer) with three channels, and DMA (direct memory access) functions. The CS5536 
companion device contains eight MFGPTs (multi-function general purpose timers) that can 
be used for a variety of functions. A number of GPIOs (general purpose input/outputs) are 
provided, and are assigned to system functions on power-up (i.e., LPC port). 
State-of-the-art power management features are attained with the division of the device into 
two internal power domains. The GPIOs and multi-function timers are distributed into each 
domain allowing them to act as wakeup sources for the device. The device provides full 
ACPI (Advanced Configuration Power Interface) compliance and supports 
industry-standard Wakeup and Sleep modes. 
For implementation details and suggestions for this device, see the supporting 
documentation (i.e., application notes, schematics, etc.) on the AMD Alchemy™ and 
Geode™ Developer Support web site. 










