Motorola M68CPU32BUG Manuel d'utilisateur télécharger pdf (Page 16)

HARDWARE PREPARATION AND INSTALLATION

M68332BCC/D 2-6 MOTOROLA

REV 1

2.3.2 RAM Chip Enable Select Header (J2)

Use the three-pin jumper header J2 (shown below) to enable/disable selection of the on-board

RAM. The BCC is shipped from the factory with the RAM chip select connected to GND via a

cut-trace short on the bottom of the BCC PCB between pins 1 and 2. A fabricated jumper is also

installed between pins 1 and 2. The cut-trace short or a fabricated jumper between pins 1 and 2

enables the BCC on-board RAM.

MCM6206

BR/CS0

GND

BG/CS1

BGACK/CS2

+5V

Fabricated Jumper

To disable the RAM from the BCC memory map, cut the trace on the solder side of the board on

J2, between pins 1 and 2, and move the fabricated jumper to pins 2 and 3. This jumper disables

selection of the on-board RAM by connecting chip enable to +5V. The chip selects are now free

for other uses. Refer to the BCC schematic diagram for more detail on RAM chip select signal

wiring.

CAUTION

Do not connect the jumper between pins 2 and 3 before removing the cut-trace

short between pins 1 and 2. Installing the jumper before the cut-trace short is

removed connects +5Vdc to ground. If +5Vdc is shorted to ground the BCC or

power supply may be damaged.

NOTE

If the cut-trace short on jumper header J2 is cut, the fabricated jumper must be

reinstalled on J2, pins 1 and 2 to return the BCC to its default setting.

1 2 ... 11 12 13 14 15 16 17 18 19 20 21 ... 67 68

Pas de commentaire

Motorola M68CPU32BUG Manuel d'utilisateur Page 16