Motorola M5271EVB, User Manual

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Chapter 1. M5271EVB Introduction 1-21
Connectors and User Components
dBUG configures the MCF5271 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.
1.5.3 User LEDs
There are eight LEDs available to the user. Each of these LEDs are pulled to +3.3V through
a 10 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 details which MCF5271 signal is associated with which LED.
1.5.4 Other LEDs
There are several other LED’s on the M5271EVB to signal to the user various
board/processor/component state. Below is a list of those LEDs and their functions:
Table 1-16. User LEDs
LED MCF5271 Signal Jumper to disconnect
D17 DTOUT0 JP13
D18 DTIN0 JP14
D19 DTOUT1 JP15
D20 DTIN1 JP16
D21 DTOUT2 JP17
D22 DTIN2 JP18
D23 DTOUT3 JP19
D24 DTIN3 JP20
Table 1-17. LED Functions
LED Function
D1-D4 Ethernet Phy functionality
D6 +3.3V Power Good
D9 +5V Power Good
D13 +1.5V Power Good (NOTE:1.5V is not enough to turn this LED on,
ignore this LED)
D15 Abort (IRQ7) asserted