Motorola M68EVB912B32, User Manual

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HARDWARE REFERENCE
68EVB912B32UM/D 4-7
The BDM interface may serve in two ways:
•
as the "probe" interface through which a host EVB in POD mode controls a target
system (see section 3.1.3)
•
as the user interface with the EVB. This requires a development tool such as
Motorola’s Serial Debug Interface. For more information, refer to the Motorola
Serial Debug Interface User’s Manual.
Table 4-3. BDM Connector Pin Assignments
Pin Number Description
W9 (in) W12 (out)
1 BKGD input to MCU BKGD output from MCU PT7
2 Vss Vss
3 no connection no connection
4 RESET* input to MCU Reset output from MCU PT6
(1)
5 no connection no connection
6 Vdd Vdd
(1)
(1)
Refer to Table 4-1. Jumper and Header Functions.
4.10 PROTOTYPE AREA
The EVB’s prototype area allows construction of custom I/O circuitry that can be connected to
the MCU’s I/O lines through connectors P2, P3, P4, and P6. This area is a grid of holes
(approximately 15 by 31) on 1/10-inch (2.54 mm) centers. This spacing accommodates most
sockets, headers, and device packages.
Figure 1-1 shows the component-side view of the prototype area. Adjacent Vss (ground) and
Vdd footprints are provided for wire-wrap pins.
4.11 MCU CONNECTORS
Four 2x20 header footprints, P2, P3, P4, and P6, surround the MCU and provide access to its I/O
and bus lines. They may be populated with wire-wrap pins or strip headers for use as I/O
connectors, connection points for instrumentation probes and target hardware, and connections to
the prototype area described in section 4.10. Figure 4-1 and Figure 4-2 depict the pin
assignments for these headers.