About These Program Examples
C-3
Program Examples
The program examples in Section C.2 and Section C.3 consist of code for
shared files and task-specific files. Table C–1 describes the shared programs.
Shared files contain code that is used by multiple task-specific files. The task-
specific programs are described in Table C–2. Every task-specific file that
uses the header files includes them by way of the
.copy assembler directive:
.copy ”init.h”
.copy ”vector.h”
The assembler brings together the .h files and .asm file. The linker links
assembled files according to the device architecture defined in the linker com-
mand file (c203.cmd).
Section C.4 contains an introduction to the procedure for using the assembler
and linker to generate code for the boot loader. Program examples are also
given in that section.
Table C–1. Shared Programs in This Appendix
Program
Functional Description
See ...
c203.cmd
Command file that defines size and placement of address blocks for
the program, data, and I/O spaces
Example C–1, page C-5
init.h
Header file that declares space for variables and constants; declares
initial values for variables; designates labels for the addresses of the
control registers mapped to on-chip I/O space; contains comments
that explain the functions of the control registers
Example C–2, page C-6
vector.h
Header file that fills the interrupt vector locations with branches to the
corresponding interrupt service routines or with other values
Example C–3, page C-7
Table C–2. Task-Specific Programs in This Appendix
Program
Functional Description
See ...
delay.asm
Creates simple nested delay loops, measurable through XF and
I/O pins
Example C–4, page
C-8
timer.asm
Generates periodic timer interrupt, XF and I/O pins toggle at the
interrupt rate
Example C–5, page
C-9
intr1.asm
Causes XF pin to toggle at the rate of the interrupt signal on the
INT1 pin
Example C–6, page
C-10
hold.asm
Explains the software logic for implementing a HOLD operation
Example C–7 page
C-11
intr23.asm
Accepts an interrupt signal on INT2 or INT3. Toggles XF pin for
each interrupt.
Example C–8, page
C-12
