PIC24FJ64GA002-I/SO Microchip Technology Inc., PIC24FJ64GA002-I/SO Datasheet - Page 55

• Manufacturer Part Number: PIC24FJ64GA002-I/SO
• Description: MCU, 16-Bit, 28-Pin, 64KB Flash, 8KB RAM, 21 I/O, Nanowatt
• Manufacturer: Microchip Technology Inc.

Specifications of PIC24FJ64GA002-I/SO

• A/d Inputs: 10 Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 16 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 21
• Interface: I2C/SPI/UART
• Memory Capacity: 64 Kbytes
• Memory Type: Flash
• Number Of Bits: 16
• Number Of Inputs: 21
• Number Of Pins: 28
• Package Type: 28-pin SOIC
• Programmable Memory: 64K Bytes
• Ram Size: 8K Bytes
• Speed: 32 MHz
• Timers: 5-16-bit
• Voltage, Range: 2-3.6 V
• Voltage, Rating: 2-3.6 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

6.0
The PIC24F interrupt controller reduces the numerous
peripheral interrupt request signals to a single interrupt
request signal to the PIC24F CPU. It has the following
features:
• Up to 8 processor exceptions and software traps
• 7 user-selectable priority levels
• Interrupt Vector Table (IVT) with up to 118 vectors
• A unique vector for each interrupt or exception
• Fixed priority within a specified user priority level
• Alternate Interrupt Vector Table (AIVT) for debug
• Fixed interrupt entry and return latencies
6.1
The Interrupt Vector Table (IVT) is shown in Figure 6-1.
The IVT resides in program memory, starting at location
000004h. The IVT contains 126 vectors, consisting of
8 non-maskable trap vectors, plus up to 118 sources of
interrupt. In general, each interrupt source has its own
vector. Each interrupt vector contains a 24-bit wide
address. The value programmed into each interrupt
vector location is the starting address of the associated
Interrupt Service Routine (ISR).
Interrupt vectors are prioritized in terms of their natural
priority; this is linked to their position in the vector table.
All other things being equal, lower addresses have a
higher natural priority. For example, the interrupt asso-
ciated with vector 0 will take priority over interrupts at
any other vector address.
PIC24FJ64GA004
non-maskable traps and unique interrupts. These are
summarized in Table 6-1 and Table 6-2.
© 2007 Microchip Technology Inc.
Note:
source
support
INTERRUPT CONTROLLER
Interrupt Vector Table
This data sheet summarizes the features
of this group of PIC24F devices. It is not
intended to be a comprehensive reference
source. For more information, refer to the
associated “PIC24F Family Reference
Manual” chapter.
family
devices
implement
PIC24FJ64GA004 FAMILY
Preliminary
6.1.1
The Alternate Interrupt Vector Table (AIVT) is located
after the IVT, as shown in Figure 6-1. Access to the
AIVT
(INTCON2<15>). If the ALTIVT bit is set, all interrupt
and exception processes will use the alternate vectors
instead of the default vectors. The alternate vectors are
organized in the same manner as the default vectors.
The AIVT supports emulation and debugging efforts by
providing a means to switch between an application
and a support environment without requiring the inter-
rupt vectors to be reprogrammed. This feature also
enables switching between applications for evaluation
of different software algorithms at run time. If the AIVT
is not needed, the AIVT should be programmed with
the same addresses used in the IVT.
6.2
A device Reset is not a true exception because the
interrupt controller is not involved in the Reset process.
The PIC24F devices clear their registers in response to
a Reset which forces the PC to zero. The micro-
controller then begins program execution at location
000000h. The user programs a GOTO instruction at the
Reset address, which redirects program execution to
the appropriate start-up routine.
Note:
is
Reset Sequence
provided
ALTERNATE INTERRUPT VECTOR
TABLE
Any unimplemented or unused vector
locations in the IVT and AIVT should be
programmed with the address of a default
interrupt handler routine that contains a
RESET instruction.
by
the
ALTIVT
DS39881B-page 53
control
bit