Interrupt Control Unit
7-23
7.3.10
Priority Mask Register (PRIMSK, Offset 2Ah)
(Master Mode)
The Priority Mask (PRIMSK) register provides the value that determines the minimum
priority level at which maskable interrupts can generate an interrupt.
Figure 7-13
Priority Mask Register (PRIMSK, offset 2Ah)
The value of PRIMSK at reset is 0007h.
Bits 15–3: Reserved—Set to 0.
Bits 2–0: Priority Field Mask (PRM2–PRM0)—This field determines the minimum priority
that is required in order for a maskable interrupt source to generate an interrupt. Maskable
interrupts with programmable priority values that are numerically higher than this field are
masked. The possible values are zero (000b) to seven (111b).
A value of seven (111b) allows all interrupt sources that are not masked to generate
interrupts. A value of five (101b) allows only unmasked interrupt sources with a
programmable priority of zero to five (000b to 101b) to generate interrupts.
Table 7-4
Priority Level
Priority
PR2–PR0
(High) 0
0 0 0b
1
0 0 1b
2
0 1 0b
3
0 1 1b
4
1 0 0b
5
1 0 1b
6
1 1 0b
(Low) 7
1 1 1b
15
7
0
0 0
0
0 0 0
0
0
0
0
0
0
PRM2
PRM1
PRM0
0
Summary of Contents for AM186EM
Page 1: ...Am186 EM and Am188 EM Microcontrollers User s Manual...
Page 4: ...iv...
Page 12: ...Table of Contents xii...
Page 62: ...Peripheral Control Block 4 10...
Page 76: ...Chip Select Unit 5 14...
Page 122: ...Timer Control Unit 8 8...
Page 136: ...DMA Controller 9 14...
Page 144: ...Asynchronous Serial Port 10 8...
Page 158: ...Programmable I O Pins 12 6...
Page 186: ...Index I 12...