Intel
®
81341 and 81342—Introduction
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
52
Order Number: 315037-002US
1.5.11
I
2
C Bus Interface Unit
There are three I
2
C (Inter-Integrated Circuit) Bus Interface Units that allow the Intel
XScale
®
processor to serve as a master and slave device residing on the I
2
C bus. The
I
2
C unit uses a serial bus developed by Philips Semiconductor consisting of a two-pin
interface. The bus allows 81341 and 81342 to interface to other I
2
C peripherals and
microcontrollers for system management functions. It requires a minimum of hardware
for an economical system to relay status and reliability information on the I/O
subsystem to an external device. Also refer to I
2
C Peripherals for Microcontrollers
(Philips Semiconductor).
1.5.12
UART Unit
The 81341 and 81342 includes two UART units. The UART Unit allows the two Intel
XScale
®
processors to serve as a master and slave device residing on the UART bus.
The UART unit uses a serial bus consisting of a two-pin interface. The bus allows 81341
and 81342 to interface to other peripherals and microcontrollers. Also refer to 16550
Device spec (National Semiconductor).
1.5.13
Interrupt Controller Unit
Each Intel XScale
®
processor supports an Interrupt Controller Unit. The Interrupt
Controller Unit (ICU) aggregates interrupt sources both external and internal of sources
of 81341 and 81342 to the Intel XScale
®
processor processor. The ICU supports high
performance interrupt processing with direct interrupt service routine vector generation
on a per source basis. Each source has programmability for masking, core processor
interrupt input, and priority.
1.5.14
Internal Bus System Controller
Each internal bus (north and south) employs a internal System Controller. The internal
System Controller observes all the address or data bus request from requestors and
completors connected to the internal bus. The internal System Controller includes
features to handle: internal address bus arbitration, internal data bus arbitration,
framing Address bus cycles, framing Data bus cycles, and provides the shared address
and shared data paths from/to units.
1.5.15
Inter-Processor Communication
Each Intel XScale
®
processor can interrupt or issue a reset to the second Intel XScale
®
processor. Each core can generate up to thirty two interrupts to the second core.
1.5.16
Inter-Processor Messaging Unit
The Inter-Processor Messaging unit provides a method for the two integrated Intel
XScale
®
processor to efficiently communicate. The hardware provides two
communication mechanisms: Doorbell Registers and Circular Queues.
1.5.17
Timers
The 81341 and 81342 supports two programmable 32-bit timers per processor. The
81341 and 81342 also supports one watchdog timer per processor.
1.5.18
GPIO
The 81341 and 81342 includes sixteen General Purpose I/O (GPIO) pins.