DSPIC33FJ64GP306 Microchip Technology Inc., DSPIC33FJ64GP306 Datasheet - Page 85

• Manufacturer Part Number: DSPIC33FJ64GP306
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

6.3
dsPIC33FJXXXGPX06/X08/X10 devices implement a
total of 30 registers for the interrupt controller:
• INTCON1
• INTCON2
• IFS0 through IFS4
• IEC0 through IEC4
• IPC0 through IPC17
• INTTREG
Global interrupt control functions are controlled from
INTCON1 and INTCON2. INTCON1 contains the Inter-
rupt Nesting Disable (NSTDIS) bit as well as the control
and status flags for the processor trap sources. The
INTCON2 register controls the external interrupt
request signal behavior and the use of the Alternate
Interrupt Vector Table.
The IFS registers maintain all of the interrupt request
flags. Each source of interrupt has a Status bit, which is
set by the respective peripherals or external signal and
is cleared via software.
The IEC registers maintain all of the interrupt enable
bits. These control bits are used to individually enable
interrupts from the peripherals or external signals.
© 2007 Microchip Technology Inc.
Interrupt Control and Status
Registers
dsPIC33FJXXXGPX06/X08/X10
The IPC registers are used to set the interrupt priority
level for each source of interrupt. Each user interrupt
source can be assigned to one of eight priority levels.
The INTTREG register contains the associated
interrupt vector number and the new CPU interrupt
priority level, which are latched into vector number
(VECNUM<6:0>) and Interrupt level (ILR<3:0>) bit
fields in the INTTREG register. The new interrupt
priority level is the priority of the pending interrupt.
The interrupt sources are assigned to the IFSx, IECx
and IPCx registers in the same sequence that they are
listed in Table 6-1. For example, the INT0 (External
Interrupt 0) is shown as having vector number 8 and a
natural order priority of 0. Thus, the INT0IF bit is found
in IFS0<0>, the INT0IE bit in IEC0<0>, and the INT0IP
bits in the first position of IPC0 (IPC0<2:0>).
Although they are not specifically part of the interrupt
control hardware, two of the CPU Control registers
contain bits that control interrupt functionality. The CPU
STATUS register, SR, contains the IPL<2:0> bits
(SR<7:5>). These bits indicate the current CPU
interrupt priority level. The user can change the current
CPU priority level by writing to the IPL bits.
The CORCON register contains the IPL3 bit which,
together with IPL<2:0>, also indicates the current CPU
priority level. IPL3 is a read-only bit so that trap events
cannot be masked by the user software.
All Interrupt registers are described in Register 6-1
through Register 6-32, in the following pages.
DS70286A-page 83