Intel C2518 FH8065501516710 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

Datasheet, Vol. 2 of 3

September 2014

502

Order Number: 330061-002US

The LPC serves as a PCI-to-ISA bridge to a number of legacy ISA devices integrated in 

the SoC and to the external LPC-1.1-compliant devices connected to the LPC interface 

pins. The bridge is discovered by the software at bus 0, device 31 (decimal), function 0.

The SoC can boot the system BIOS and the system firmware through the LPC bus or 

through the Serial Peripheral Interface (SPI). The software selects which of these two 

BIOS/firmware boot sources to use. The BIOS Soft-Strap register (RCBA+00h[11:10]) 

must be set to 11b (default) to boot from SPI or 00b to boot from the LPC. This is 

The LPC interface is used for connection of various legacy components.

The SoC does not support bus-mastering devices on the LPC interface. Such devices 

are bi-directional parallel ports, IR controllers, and floppy drive controllers. The LPC 

does support DMA and what is known as PHOLD, the mechanism for an ISA device to 

lock the system so that it performs DMA. Super I/O devices that depend on DMA are 

not supported. If one of these devices is connected to the LPC and a PHOLD is 

requested, the SoC drops the request, sets an error bit, and the system hangs 

immediately.

This does not impact other legacy devices such as serial ports, keyboard/mouse, and 

USB-based peripherals.