PRIGROUP Initialization

[geoffreymbrown]

Posted on January 13, 2012 at 14:56

I can't figure out how the PRIGROUP is initialized in the stm32.  In PM0056 (Programming manual)  it appears the SCB_AIRCR register field for PRIGROUP is initial 0, but the table defining PRIGROUP (table 45) has no entry for a PRIGROUP = 0b000.

What am I missing ?   I'd like to understand the default (i.e. reset) behavior.

[Tesla DeLorean]

Posted on January 13, 2012 at 17:05

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0552a/Cihehdge.html

Absent the hardware supporting 8 bits, 0b000 is the equivalent to 0b011 if I'm not mistaken. The STM32 only implements the top 4 bits.

[infoinfo989]

Posted on January 14, 2012 at 00:24

In addition to Clive's suggestion, take a look at the comment block in misc.c  I found that very helpful in understanding ST's implementation.