User`s guide

MPLAB
®
IDE User’s Guide
DS51519B-page 208 © 2006 Microchip Technology Inc.
Program memory, or core, instruction length is used to group PICmicro MCUs. Data
memory is 8-bit for these devices.
At the time this documentation was produced, the following cores are associated with
the listed devices:
• 12-bit Core – PIC12C5XX, PIC12CE5XX, PIC16X5X, PIC16C505
• 14-bit Core – PIC12C67X, PIC12CE67X, PIC12F629/675, PIC16
• 16-bit Core – PIC17
• 16-bit Core – PIC18
The 12-bit, 14-bit and 16-bit (PIC17) core devices have word-addressed program
memory space.
The 16-bit (PIC18) core devices have a byte-organized program memory space. There
are some restrictions in the silicon on how the program memory space can be
accessed, especially when using long writes to program memory. The simulator may
not show the same restrictions in all situations. Consult the data sheet for proper
operation.
The dsPIC digital signal controller (DSC) is a combination of a digital signal processing
(DSP) core and PICmicro microcontroller (MCU) peripheral features. PIC24 MCUs are
basically dsPIC DSC devices without DSP capability. Both devices use a modified Har-
vard architecture to provide separate 24-bit program memory and 16-bit data memory
spaces.
At the time this documentation was produced, the following were available devices of
this type:
• dsPIC30F
• dsPIC33F
•PIC24
16.3.1 Pin Simulation – All Devices
MPLAB SIM only simulates to the register level, not the pin level, e.g., RB0 represents
the value in bit0 of the PORTB register, not the value on the pin named RB0. This
makes sense as the simulator is a software model, and not actual device hardware.
In general, bit/pin binary values are interchangeable. However, A/D operation requires
that the corresponding port register read ‘0’, which may be different from what would
be on an actual pin. This can impact the operation of ADC and comparators. Please
see the Peripheral section for more on how these are simulated.
Device I/O pins may be multiplexed with other peripherals (and therefore referred to by
more than one name). The simulator recognizes only the pin names specified in the
standard device headers as valid I/O pins. Therefore, you should refer to the header
file for your device (pDeviceNumber.inc) to determine the correct bit/pin names.
Most multiplexed bit/pin names may be used interchangeably, e.g., for the PIC18F8720
pin RF2/AN7/C1OUT, you may use RF2 or AN7 or C1OUT (although it is recom-
mended that you use the appropriate name for peripheral function you are using). Basi-
cally, AN7 and C1OUT are aliases for RF2. The only exception to this is when there is
a multiplexed peripheral function across multiple ports. In this case, the function name
is not selectable; you must choose the corresponding port bit/pin name.