Square 1 Electronics' latest new book, "Mov'n Up, Migrating
from the PICŪ Microcontroller 16 Series to the 18 Series," contains
information on the 18 Series devices which have some features that make them
easier to use. Program memory paging is gone, so tables may be of any length and
may be located anywhere. Data memory bank selection is simplified. Compare, bit
toggle and set file instructions make writing programs easier. Context saving on
interrupt is automatic (sometimes). The newer application peripherals (CAN bus,
etc.) are in the 18 Series devices. "Mov'n Up" will save you a lot of time by
providing an explanation of the fundamental differences (vs. 16 Series), along
with programming examples, to make the transition easier. The complete table of
contents follows:
INTRODUCTION
18 Series introduction
Why use 18 series devices?
18 Series - New and different features summary
Software/Programming
Hardware
AN716
Example - PIC18F1220
Circuit for PIC18F1220 experiments
Device programming methods
18 Series device programming considerations
18 Series - first look
18 Series instruction set
Most useful new instructions
Move or define data - data memory
Table operations - program memory
Change register contents
Control program flow
Arithmetic
Less useful new instructions
Instructions that have been changed
Instructions not discussed here
Access designator
Using some of the new instructions
18 Series I/O ports
Dealing with 2 and 3-byte registers designated by a label
18 Series data memory
Data memory map - PIC18F1220
Banking and the access bank
Bank select register (BSR)
Data memory table operations - indexed addressing
LFSR Instruction
MOVFF instruction
18 Series special function registers - overview
18 Series program memory table read operations
Creating tables
Identifying tables
Pointing
Example - create a table and read data in the first location
Example - create a table and read data in the third location
by incrementing the table pointer
Example - create a table and read data in the fourth location
by adding the offset to the table pointer
Example - create a table and read data in the fifth location
using a loop with a counter
Example - create an ASCII text message in a table - use counter
to detect end
Schematic for ASCII text message examples
Example - create an ASCII text message in a table - use null
character to detect end
Example - create an ASCII text message in a table - use null
character to detect end - second line of data
Example - create a text string - use null character to detect end
Example - create an ASCII character string - use null character
to detect end
Tables of numbers
18 Series interrupts
New features
How 18 series interrupts work
Interrupt register comparisons - PIC16F870 vs. PIC18F1220
Prioritized interrupts
Priority interrupts disabled
Priority interrupts enabled
Interrupting an interrupt
Interrupt vectors
Context saving
Prioritized interrupts experiment
Schematic for prioritized interrupts experiment
18 Series configuration registers
PIC18F1220 configuration registers (example)
__config method
Configuration register 1H - oscillator
Configuration register 2H - watchdog timer
Configuration register 2L - brown-out reset and power-up timer
Configuration register 3H - MCLR
Configuration register 4L - debug, low voltage programming, stack
Configuration register 5H - code protection
Configuration register 5L - code protection
Configuration register 6H - write protection
Configuration register 6L - write protection
Configuration register 7H - table read protection
Configuration register 7L - table read protection
PIC18F1220 - example
Pins and functions
Package
Ports
Architecture - overview
Program memory
Data memory
Peripheral control registers - overview of selected registers
Clock oscillator options
Internal clock
OSCCON register
External clock modes
Peripherals
Timers and counters
TMR0
TMR1
TMR2
CCP module
A/D
USART
Appendix A - USART in brief
RS-232 interface for a PIC microcontroller
Using a Windows terminal program
PIC microcontroller-to-PIC serial communication
Appendix B - Program listings vs. page number
