LPC Super I/O SIO/LPC Slot, Serial, IrDA, Clocks

Theory of Operation—Mobile Intel® 915GME Express Chipset

3.4.2.7LPC Super I/O (SIO)/LPC Slot

An SMSC LPC47N207 serves as the SIO on the Mobile Intel® 915GME Express Chipset platform. Shunting the jumper at J7E4 to the 2-3 positions can disable the SIO by holding it in reset. This allows other SIO solutions to be tested in the LPC slot at J8F2. A sideband header is provided at J9G2 for this purpose. This sideband header also has signals for LPC power management. Information on this header is on sheet 29 of the Mobile Intel® 915GME Express Chipset schematics and is detailed in the “LPC Slot and Sideband Header Specification” (see Table 3, “Related Documents” on page 13).

3.4.2.8Serial, IrDA

The SMSC SIO incorporates a serial port, and IrDA (Infrared), as well as general purpose IOs (GPIO). The serial port connector is provided at J2A1A, and the IrDA transceiver is located at U4A2. The IrDA transceiver on Mobile Intel® 915GME Express Chipset supports both SIR (slow IR) and CIR (Consumer IR). The option to select between the two is supported through software and GPIO pin on the SIO.

3.4.2.9BIOS Firmware Hub (FWH)

The 8 Mbit Flash device used on the Mobile Intel® 915GME Express Chipset to store system and video BIOS as well as an Intel Random Number Generator (RNG) is a socketed E82802AC8 a 32-pin PLCC package. The reference designator location of the FWH device is U8G1. The BIOS can be upgraded using an MS-DOS* based utility and is addressable on the LPC bus off of the ICH6-M.

3.4.2.10System Management Controller (SMC)/Keyboard Controller

The Hitachi* H8S/HD64F2 serves as both SMC and KBC for the platform. The SMC/KBC controller supports two PS/2 ports, battery monitoring and charging, EMA support, wake/runtime SCI events, and power sequencing control. The two PS/2 ports on the Mobile Intel® 915GME Express Chipset are for legacy keyboard and mouse. The keyboard plugs into the bottom jack and the mouse plugs into the top jack at J1A2. Scan matrix keyboards can be supported via an optional connector at J9E2.

3.4.2.11Clocks

The Mobile Intel® 915GME Express Chipset board uses a CK-410M and CK-SSCD compatible solution. The CK-SSCD solution offers improved EMI performance by spreading the radiated clock emissions over a wider spectrum than a single frequency. This is accomplished while controlling the clock frequency deviation such that system performance is not compromised. The FSB frequency is determined from decoding the processor BSEL settings.

3.4.2.12Real Time Clock

An on-board battery at BT5H1 maintains power to the real time clock (RTC) when in a mechanical off state. A CR2032 battery is installed on the Mobile Intel® 915GME Express Chipset development kit.

3.4.2.13Thermal Monitoring

The processor has a thermal diode for temperature monitoring. The SMC thermal monitoring device will throttle the processor if it becomes hot. If the temperature of the processor rises too high, the SMC will alternately blink the CAPS lock and NUM lock LEDs on the board, and the board will shut down.

	Mobile Intel® 915GME Express Chipset
April 2007	Development Kit User’s Manual
Order Number: 317230-001US	25