Intel C2550 FH8065401488912 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

September 2014

Datasheet, Vol. 2 of 3

Order Number: 330061-002US

529

Besides the 14.31818-MHz clock supplied to the SoC, one signal pin is associated with 

the integrated 8254 PIT.

The signal description table has the following headings:

• Signal Name: The name of the signal/pin
• Direction: The buffer direction is either input, output, or I/O (bi-directional)
• Type: The buffer type
• Description: A brief explanation of the signal function

Accessed through 8-bit registers mapped to the I/O space using 16 address bits:

• I/O addresses 0x40-0x43, aliased to 0x50-0x53

Has three internal counters/timers:

• 8254 Timer 0 - Used for OS timer tick.

— Mapped to IRQ0 on 8259, IRQ2 on I/O APIC.
— Typically set to 1-ms to 50-ms period.

• 8254 Timer 1 - No longer used (was for ISA refresh).
• 8254 Timer 2 - “Beep” speaker.

OD