DV164101 Microchip Technology, DV164101 Datasheet - Page 64
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DV164101
Manufacturer Part Number
DV164101
Description
KIT DEV PICKIT1 FLASH 8/14PIN
Manufacturer
Microchip Technology
Series
PICkit™ 1r
Type
MCUr
Specifications of DV164101
Contents
PIC Kit 1 Circuit Board, CD-ROMs, USB Interface Cable and Booklet
Processor To Be Evaluated
PIC12F675
Interface Type
USB
Silicon Manufacturer
Microchip
Core Architecture
PIC
Core Sub-architecture
PIC12, PIC16
Silicon Core Number
PIC12F, PIC16F
Silicon Family Name
PIC12F6xx, PIC16F6xx
Rohs Compliant
NA
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
For Use With/related Products
Microchip's 8-14 Pin FLASH Microcontrollers
For Use With
AC164122 - BOARD DAUGHT PICTAIL SD/MMC CARDAC164120 - BOARD SIGNAL ANALYSIS PICKIT
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
DV164101R
DV164101R
DV164101R
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
DV164101
Manufacturer:
Microchip Technology
Quantity:
135
PICkit
C.7
DS40051D-page 60
LESSON 5 – PROGRAM MEMORY LOOK-UP ROUTINES
™
1 Flash Starter Kit User’s Guide
There is often a need to store constants or strings in a PIC microcontroller. Storing this
information in program memory is the best solution as long as this data never needs to
change and program memory is available. Program memory is non-volatile, therefore,
it will maintain information regardless of V
This lesson demonstrates how to retrieve data from Program Memory. It covers the
following topics:
• What a program memory look-up table is
• How a program memory look-up table is implemented
• Why a program memory look-up table is useful
C.7.1
Constants stored in program memory are accessed via look-up tables. A look-up table
is similar to a computed goto (see Lesson 2) only instead of a list of goto statements,
after incrementing the program counter, there is a list of retlw instructions. Each
retlw instruction is followed by one byte of the information. Example C-3 shows a
look-up table for the string “Microchip” written in assembly language.
EXAMPLE C-3:
For this lesson, constants corresponding to a sequence of LEDs are stored in a
program memory look-up table. For instance, the first constant stored is 5F. This
corresponds to the binary number “01011111”. Each bit corresponds to an LED,
therefore, LEDs D0, D1, D2, D3, D4 and D6 will be lit when this constant is accessed.
After each look-up table, the value is displayed on the LEDs in the same fashion as
discussed in Lesson 3, using the Timer0 interrupt. The appearance of more than one
LED being lit at a time is possible because the LEDs are multiplexed fast enough that
the human eye can not detect the LEDs being turned on and off. When SW1 is pressed,
an interrupt-on-change is generated to increment the lookup to the next location.
Figure C-14 shows the flowchart for this example.
LookupProgramMemory
StartTable
movlw
movwf
movlw
addwf
btfsc
incf
movwf
retlw
retlw
retlw
retlw
retlw
retlw
retlw
retlw
retlw
Design
high StartTable
PCLATH
low StartTable
index, w
STATUS, C
PCLATH, f
PCL
"
"
"c"
"r"
"o"
"c"
"h"
"i"
"p"
M
i
LOOK-UP TABLE WRITTEN IN ASSEMBLY
"
"
DD
voltage levels or PIC microcontroller reset.
2004 Microchip Technology Inc.