Table 50. Priority Grouping - ST STM32F4 Series Programming Manual

Core peripherals
bits you might require more explanation here, and want to remove invalid rows from the
table, and modify the entries in the number of columns.
PRIGROUP
[2:0]
0b0xx
0b100
0b101
0b110
0b111
1. PRI_n[7:4] field showing the binary point. x denotes a group priority field bit, and y denotes a subpriority
field bit.
Determining preemption of an exception uses only the group priority field, see
Interrupt priority grouping on page
228/260

Table 50. Priority grouping

Interrupt priority level value, PRI_N[7:4]
Binary Group priority
(1)
point bits
0bxxxx [7:4]
0bxxx.y [7:5]
0bxx.yy [7:6]
0bx.yyy [7]
0b.yyyy None
40.
DocID022708 Rev 6
Subpriority Group
bits priorities
None 16
[4] 8
[5:4] 4
[6:4] 2
[7:4] None
PM0214
Number of
Sub
priorities
None
2
4
8
16
Section 2.3.6: