MPC8378E datasheet(79/128 Pages) FREESCALE

79 / 128 page

MPC8378E PowerQUICC II Pro Processor Hardware Specifications, Rev. 8

Freescale Semiconductor

This figure shows the SPI timing in master mode (internal clock).

Figure 53. SPI AC Timing in Master Mode (Internal Clock) Diagram

20 High-Speed Serial Interfaces (HSSI)

This chip features two serializer/deserializer (SerDes) interfaces to be used for high-speed serial

interconnect applications. See Table 1 for the interfaces supported.

This section describes the common portion of SerDes DC electrical specifications, which is the DC

requirement for SerDes reference clocks. The SerDes data lane’s transmitter and receiver reference circuits

are also shown.

20.1

Signal Terms Definition

The SerDes utilizes differential signaling to transfer data across the serial link. This section defines terms

used in the description and specification of differential signals.

Figure 54 shows how the signals are defined. For illustration purpose, only one SerDes lane is used for

description. The figure shows waveform for either a transmitter output (SDn_TX and SDn_TX) or a

receiver input (SDn_RX and SDn_RX). Each signal swings between A volts and B volts where A > B.

Using this waveform, the definitions are as follows. To simplify illustration, the following definitions

assume that the SerDes transmitter and receiver operate in a fully symmetrical differential signaling

environment.

•

Single-Ended Swing

The transmitter output signals and the receiver input signals SDn_TX, SDn_TX, SDn_RX and

SDn_RX each have a peak-to-peak swing of A – B volts. This is also referred as each signal wire’s

single-ended swing.

•

Differential Output Voltage, VOD (or Differential Output Swing):

The differential output voltage (or swing) of the transmitter, VOD, is defined as the difference of

the two complimentary output voltages: VSDn_TX – VSDn_TX. The VOD value can be either positive

or negative.

SPICLK (output)

tNIIXKH

tNIKHOV

Input Signals:

SPIMISO

(See Note)

Output Signals:

SPIMOSI

(See Note)

Note: The clock edge is selectable on SPI.

tNIIVKH

MPC8378E Datasheet(PDF) 79 Page - Freescale Semiconductor, Inc