80333 Datasheet, PDF (13/75 Pages) Intel Corporation – I/O Processor

80333
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DMA Controller
The DMA Controller allows low-latency, high-throughput data transfers between PCI bus agents
and the local memory. Two separate DMA channels accommodate data transfers to the PCI bus.
Both channels include a local memory to local memory transfer mode. The DMA Controller
supports chaining and unaligned data transfers. It is programmable through the Intel XScale^® core
only.
I²C Bus Interface Unit
The I²C (Inter-Integrated Circuit) Bus Interface Unit allows the Intel XScale^® core to serve as a
master and slave device residing on the I²C bus. The I²C unit uses a serial bus developed by Philips
Semiconductor*, consisting of a two-pin interface. The bus allows the 80333 to interface to other
I²C peripherals and microcontrollers for system management functions. It requires a minimum of
hardware components for an economical system to relay status and reliability information on the
I/O subsystem to an external device. Also refer to I²C Peripherals for Microcontrollers (Philips
Semiconductor).
The 80333 includes two I²C bus interface units.
Messaging Unit
The Messaging Unit (MU) provides data transfer between the PCI system and the 80333. It uses
interrupts to notify each system when new data arrives. The MU has four messaging mechanisms:
• Message Registers
• Doorbell Registers
• Circular Queues
• Index Registers
Each messaging mechanism allows a host processor or external PCI device and the 80333 to
communicate through message passing and interrupt generation.
Internal Bus
The Internal Bus is a high-speed interconnect between internal units and Intel XScale^® core
processor. The Internal Bus operates at 333 MHz and is 64 bits wide.
UART Units
The 80333 includes two UART unit. The UART units allow the Intel XScale^® core to serve as a
master and slave device residing on the UART bus. The UART units use a serial bus consisting of a
four-pin interface. The bus allows the 80333 to interface to other peripherals and microcontrollers.
Also refer to 16550 Device Specification (National Semiconductor*).
Datasheet
Intel^® 80333 I/O Processor Datasheet
Order Number: 305433, Revision: 002
May 2005
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