|GPC-114 Universal Controller |
GCP-114 controller card is
manufactured in Italy by Grifo.
This is an excellent card for
small projects requiring communication over the RS232/422/485
interface, process control based on RTC with 8-channel analog
input, digital input/output or data collection via Abaco I/O
Flexible memory configuration
allows to configure this card for use with the battery
backed-up SRAM, EPROM or EEPROM.
Java application example described on this page shows how to
use Java VM for 68HC11 with this controller board.
GPC-114 has been configured
port for communication with host PC
battery backed-up SRAM
SRAM (no backup)
EPROM (J6 & J7 closed)
'boot' switch connected to MODA/MODB pins of 68HC11 to
allow loading programs from the host PC
A simple menu driven
application has been written that can perform following tasks:
and receive data from the host PC via RS232
display of current date & time
12/24 time format
Application is controlled
from the host PC running the serial communication software
like HyperTerminal under Windows or Minicom under Linux.
When Java program is started
it transmits welcome message and shows list of available
commands. It then waits for a command from the host PC. When a
'Show Date/Time' command is received Java program continuously
transmit current time read from RTC chip.
Java application source code
is available in zip format. After downloading unzip the
GPC114.ZIP into folder where you have previously installed
Java VM for 68HC11. Use unzip utility that supports long file
names with create sub-folders option enabled. The binary size
of this Java application is about 9.7KB.
What is required:
GPC-114 memory map
68HC11 interrupt vectors
Java VM + interrupt
vectors redirection code
Time Clock registers
board resources - Abaco Bus, /ECS1
collected application heap
CPU control registers
Native code, Java VM
Real interrupt vectors
One special feature worth
noting is that the interrupt vectors are located at $100 and
are set when startup/native code is loaded into memory. When
an interrupt occurs, special interrupt handling code in the
EPROM fetches real vectors from corresponding offsets at
$100. This feature allows to have Java VM permanently loaded
in the EPROM. There is no need to re-program EPROM every
time a new Java application is loaded.