SW006010 Microchip Technology, SW006010 Datasheet - Page 57

• Manufacturer Part Number: SW006010
• Description: MPLAB 17C SOFTWARE
• Manufacturer: Microchip Technology

Specifications of SW006010

• Tool Function: Compiler
• Tool Type: Compiler
• Processor Series: PIC17C
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: MPLAB®
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5.5
5.6
5.7
 2002 Microchip Technology Inc.
MEMORY MODELS
LOCATING CODE
LOCATING DATA
Different devices access memory differently. Depending on your selected device, you
will need to use different memory model versions of libraries and/or precompiled
object files. See the MPLAB C17 C Compiler Libraries (DS51296) for a list of libraries
and precompiled object files available for different memory models.
For PIC17 devices with program memory (ROM) over 8K, the memory is broken up in
to pages. For PIC17 devices with data memory (RAM) over 256, the memory is
broken up into banks. Table 5.1 spells out the memory models available for these
devices via MPLAB C17.
Table 5.1: Memory Model Usage – MPLAB C17
The usage of the keywords near, far, ram and rom is discussed in Chapter 6.
5.6.1
Following a
until another
location of code to a specific address.
For example:
5.6.2
Code sections that have the
overlaps other overlay code sections. This feature is generally not needed, but could
be useful with multiple external memory sources.
For example:
5.7.1
The different types of data sections are:
• udata: Statically allocated uninitialized global data is placed here. Used for data
• idata: Statically allocated initialized global data goes here. Used for data memory
• romdata: Variables declared with the
#pragma code myCode=0x2000
#pragma code overlay myScnName=0x1000
memory allocation.
allocation.
program memory allocation.
m
s
c
l
Memory Model
Section Types Used to Place Code
Attributes – Overlay
Section Types Used to Place Data
#pragma code
#pragma code
small
medium
compact
large
, all generated code will be assigned to the specified section
near rom – program memory ≤ 8K,
near ram – data memory ≤ 256
far rom – program memory > 8K,
near ram – data memory ≤ 256
near rom – program memory ≤ 8K,
far ram – data memory > 256
far rom – program memory > 8K,
far ram – data memory > 256
is encountered. An absolute code section allows the
overlay
attribute can be located at an address that
rom
Runtime Environment
attribute are placed here. Used for
Device Description
apRNOVM^-page 51
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