Normal Interrupt Mask Register; Table 10-5 Normal Interrupt Mask Register Description - Motorola DragonBall MC9328MX1 Reference Manual

10.4.2 Normal Interrupt Mask Register

The Normal Interrupt Mask Register (NIMASK) controls the normal interrupt mask level. All normal
interrupts with a priority level less than or equal to the NIMASK are disabled. The priority levels of normal
interrupts are determined by the normal interrupt priority level registers (NIPRIORITY7, NIPRIORITY6,
NIPRIORITY5, NIPRIORITY4, NIPRIORITY3, NIPRIORITY2, NIPRIORITY1, and NIPRIORITY0).
The reset state of this register does not disable any normal interrupts.
Writing all 1's, or 1, to the NIMASK sets the normal interrupt mask to
–
interrupt priority levels.
This hardware mechanism creates reentrant normal interrupt routines by disabling lower priority normal
interrupts. Refer to Section 10.5.6, "Writing Reentrant Normal Interrupt Routines," on page 10-36 for
more details on the use of the NIMASK register.
This register is located on the ARM920T processor's native bus, is accessible in 1 cycle, and can be
accessed only in supervisor mode. This register must be accessed only on word (32-bit) boundaries.
NIMASK
BIT 31 30 29
TYPE r r r
0 0 0
RESET
BIT 15 14 13
TYPE r r r
0 0 0
RESET
Table 10-5. Normal Interrupt Mask Register Description
Name
Reserved Reserved—These bits are reserved and should read 0.
Bits 31–5
NIMASK Normal Interrupt Mask—Controls normal
Bits 4–0 interrupt mask level. All normal interrupts
of priority level less than or equal to the
NIMASK are disabled. Settings are shown
in decimal. Setting bit 4 disables all normal
interrupts.
MOTOROLA
Normal Interrupt Mask Register
28 27 26 25
r r r r
0 0 0 0
12 11 10 9
r r r r
0 0 0 0
Description
Interrupt Controller (AITC)
1 and does not disable any normal
–
24 23 22 21 20
r r r r r
0 0 0 0 0
0x0000
8 7 6 5 4
r r r r rw
0 0 0 0 1
0x001F
Settings
0 = Disable priority level 0 normal interrupts
1 = Disable priority level 1 and lower normal interrupts
...
16+ = Disable all normal interrupts.
Programming Model
Addr
0x00223004
19 18 17 16
r r r r
0 0 0 0
3 2 1 0
NIMASK
rw rw rw rw
1 1 1 1
10-9