Motorola ColdFire MCF5282 User Manual download pdf (Page 32)

1-20 M5282EVB User’s Manual

PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE

Connectors and User Components

A hard reset and voltage sense controller (U12) is used to produce an active low power-on RESET

signal. The reset switch S2 is fed into U12 which generates the signal which is fed to the MCF5282

reset, RSTI. The RSTI signal is an open collector signal and so can be wire OR’ed with other reset

signals from additional peripherals.

dBUG configures the MCF5282 microprocessor internal resources during initialization. The

instruction cache is invalidated and disabled. The Vector Base Register, VBR, contains an address

which initially points to the Flash memory. The contents of the exception table are written to

address $00000000 in the SDRAM. The Software Watchdog Timer is disabled, the Bus Monitor is

enabled, and the internal timers are placed in a stop condition. The interrupt controller registers are

initialized with unique interrupt level/priority pairs.

1.5.4 User LEDs

There are four LEDs available to the user. Each of these LEDs are pulled to +3.3V through a 470

ohm resistor and can be illuminated by driving a logic “0” on the appropriate signal to “sink” the

current. Each of these signals can be disconnected from it’s associated LED with a jumper. The

table below which MCF5282 signal is associated with LED.

1.5.5 Other LEDs

There are several other LED on the M5282EVB to signal to the user various board/processor/component state. Below

is a list of those LEDs and their functions:

Table 1-22. User LEDs

LED MCF5282 Signal Jumper to disconnect

D6 DTOUT0 JP12

D7 DTOUT1 JP13

D8 DTOUT2 JP14

D9 DTOUT3 JP15

Table 1-23. LED Functions

LED Function

D1-D5 Ethernet Phy functionary (See AMD - AM79C874VC documentation)

D6-D9 User LEDs (See Table 1-22., “User LEDs”)

D11 +3.3V Power Good

D14 +5V Power Good

D15 Abort (IRQ7

) asserted

D16 Reset (RSTI) asserted

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Motorola ColdFire MCF5282 User Manual Page 32