MPC821 datasheet(61/242 Pages) NXP

61 / 242 page

Functional Description

MPC8XXFADS Design Specification—Rev 0.1

PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE

has a 10 pin header connector matching the one on the FADS.

In this mode of operation, the on-board debug port controller, is connected to the target system’s

debug-port connector (see 4•12•1•1 "Debug Port Connection - Target System Requirements"

below). Since DSDO signal is driven by the MPC, it is a must, to remove the local MPC from its

socket, to avoid contention over this line.

When either the local MPC is removed from its socket or the daughter board is removed from the

FADS, all FADS’s modules are inaccessible, except for the debug-port controller. All module-enable

indications are darkened, regardless of their associated enable bits in the BCSR. Pull-up resistors are

connected to Chip-Select lines, so they do not float when the MPC is removed from its socket,

avoiding possible contention over data-bus lines.

4•12•1•1 Debug Port Connection - Target System Requirements

In order for a target system may be connected to the FADS, as a debug port controller, few measures

need to be taken on the target system:

A 10-pin header connector should be made available, with electrical connections matching

FIGURE 4-8 "Standard Debug Port Connector" on page 61.

Pull-down resistors, of app. 1K

Ω should be connected over DSDIA and DSCKA signals.

These resistors are to provide normalB operation, when a debug-port controller, is not con-

nected to the target system

The debug-port should be enabled and routed to the desired pins. See the DBGC and

DBPC fields within the HARD-RESET configuration word.

4•12•2

Debug Port Control / Status Register

The control / status register is an 8 bit register (bit 7 stands for MSB). For the description of the ADI

A. Remember that the location of DSDI and DSCK is determined by the HARD-Reset configuration.

B. Normal - i.e., boot via CS0~.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

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