3
1.3 SYSTEM MEMORY
There are two 32-pin sockets on the board for EPROM’s or Flash ROM’s (U13, U14), U13 is the most
significant byte and the U14 is the least significant byte. The EPROM sockets can be set up via jumpers
(JP2, JP3, and JP4) to accept 27C256, 27C512, 27C010, 27C020, 27C040, and 27C080 EPROM’s. or
29F010, and 29F040. The SBC5204 comes with two 29F010 Flash ROM’s which are programmed with
a debugger/monitor firmware. The dBUG driver only supports 29F010 Flash ROM.
There are two 32-pin sockets for SRAM’s which can accept 128Kx8 and 512Kx8 SRAM’s. JP2 is used to
make the selection.
1.4 SERIAL COMMUNICATION CHANNELS
The MCF5204 has one built-in Serial Communication Channel with baud rate generator. This signals of
this channel are passed through external Driver/Receivers to make the channel compatible with RS-232.
This channel is not used by the debugger and is available to user. The SBC5204, however, has one
MC68HC901 which has four timers and a serial communication port. One timer channel is used as baud
rate generator for the serial channel. The RXD and TXD lines are passed through external Driver/Receiver
to make this channel compatible with RS-232C level (Note: only 2 main signals are available, RXD and
TXD signals). This channel is the “TERMINAL” channel used by the debugger for communication with
external terminal/PC.
1.5 PARALLEL I/O PORTS
Some of the multifunction pins of the MCF5204 can be used as Port A general purpose I/O pins. These
pins are available to user except A20/PA0 which may be used for EPROM selection when using 8M
EPROM’s.
1.6 PROGRAMMABLE TIMER/COUNTER
The MCF5204 has two built in general purpose timer/counters. These timers are not used by the debugger
and are available to the user. The signals for the timer share the pins with Port A and are available on the
connector J9. There are also three timers in MC68HC901 which are available to user.
1.7 ISA BUS CONNECTOR
The SBC5204 has one ISA bus connector to allow the use of off-the-shelf ISA I/O cards. The main reason
for this connector is to install an Ethernet card to support down-load via network.
1.8 SYSTEM CONFIGURATION
The SBC5204 board requires only the following items for minimum system configuration (Fig. 1.2):
a. The SBC5204 board (provided).
b. Power supply ( +5 Vdc regulated or 7.5V to 12V DC), about 0.5 Amp.
c. RS-232C compatible terminal or a PC with terminal emulation software.