C5C5EDELTA-RMSLASHD datasheet(23/114 Pages) NXP

23 / 114 page

Executive Processor

The Executive Processor (XP) serves as a centralized computing resource for the C-3e NP

and manages the system interfaces.

The XP performs conventional supervisory tasks in the C-3e NP, including:

• Reset and initialization of the C-3e NP

• Program loading and control of CPs

• Centralized exception handling

• Management of a host interface through the PCI

• Management of system interfaces (PCI, Serial Bus, PROM)

System Interfaces

The system interfaces to the XP are:

• PCI — Provides an industry standard 32bit 33/66MHz PCI channel used for chip-level

shared resources. The PCI has both initiator and target capabilities. The PCI interface is

typically connected to a host processor.

• Serial Bus Interface — Provides a general purpose bi-directional, two-wire serial bus

and I/O port that allows the C-3e NP to control external logic with either of two

standard protocols:

– The MDIO (high-speed) protocol: uses a 16bit data format with 10bits of

addressing and supports transfers up to 25MHz.

– The low-speed protocol: uses an 8bit data format followed by an acknowledge bit

and supports transfers up to 400kbps.

Software is used to select which protocol to use, by setting the appropriate bits in the

Serial Bus Configuration Register. When a serial bus transfer is active, an external pin is

driven by the C-3e NP to indicate which protocol is being used (SPLD=0 indicates

MDIO protocol; SPLD=1 indicates low-speed protocol).

Both SIDA and SICL are bi-directional lines that are connected, via an external pull-up

resistor, to a positive supply voltage. When the bus is free, both lines are HIGH because

of the pull-up resistor. The output stages of the devices connected to the bus must

have either an open-drain or open-collector in order to perform the wired-AND

function required for its arbitration mechanism.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

C5C5EDELTA-RM/D 数据表(PDF) 23 Page - NXP Semiconductors