Interrupt Handlers
8-17
DSP Private Peripherals
Table 8–21. Level 1 Interrupt Mapping (Continued)
Level 1 Interrupt
DSP
IFR_bit/IMT_bit (26:0)
Vector
Location
DSP
Interrupt
Priority
DMA_channel_0
12
INT18
FFFF90
18
Mailbox 2
16
INT19
FFFF98
19
DMA_channel_2
19
INT20
FFFFA0
20
DMA_channel_3
20
INT21
FFFFA8
21
TIMER2
23
INT22
FFFFB0
22
TIMER1
24
INT23
FFFFB8
23
8.4.2
Level 2 Interrupts
The level 2 interrupt controller provides up to 16 prioritized and maskable inter-
rupts to the DSP core.
The level 2 interrupt controller resides on the 16-bit TI peripheral bus. This
module is clocked by the DSP_INTH_CK clock, which is fixed at half the
CK_GEN2 frequency (see Chapter 15 for details). Configuration registers
configure incoming interrupts as level-sensitive or edge-sensitive interrupts.
One interrupt-level register (ILR) is associated with each incoming interrupt.
It assigns a priority to the corresponding interrupt,determines whether it is to
be level- or edge-sensitive, and determines to which DSP interrupt (fast inter-
rupt request (FIQ) or low priority interrupt request (IRQ)) the incoming interrupt
goes. If several interrupts have the same priority level assigned, they are
serviced in a predefined order.
All level 2 interrupts are routed to FIQ. IRQ output is unconnected.
The interrupt controller also provides a 16-bit software interrupt register. This
16-bit register corresponds to the same 16-bit external interrupt lines. By writ-
ing a 1 to the targeted bit, an interrupt is generated if the corresponding ILR
is set to edge sensitive; otherwise, no interrupt is generated. External interrupt
request and internal software request are ORed together first before being
sent to the interrupt controller to be serviced. The software interrupt register
is always read back with a zero. This allows simulation of external interrupts
to test the corresponding interrupt driver by using the software interrupt
mechanism at any time.
The FIQ outputs from the interrupt controller are reset by writing a 1 to the
corresponding bit of the control register.