标签：gic
这组寄存器主要是用来设置中断的优先级，每个寄存器可以设置4个中断的优先级，每个中断对应8个bit位，由此可知每个中断的优先级的设置值最大为255，最小为0，数值越小，表示中断优先级越高，寄存器相对于distributor基地址的偏移区间为0x400-0x7f8；
此组寄存器的个数由GICD_TYPER.ITLinesNumber 的值决定，为(8 * (GICD_TYPER.ITLinesNumber+1))个； 每个寄存器划分的4个设置域为：
[31:24] Priority, byte offset 3
[23:16] Priority, byte offset 2
[15:8] Priority, byte offset 1
[7:0] Priority, byte offset 0
每个中断设置自己中断优先级所操作的寄存器及每个寄存器的哪个域的计算方法为：
For interrupt IDm, when DIV and MOD are the integer division and modulo operations:
the corresponding GICD_IPRIORITYRnnumber, n, is given byn = mDIV 4
the offset of the required GICD_IPRIORITYRnis (0x400+ (4*n))
the byte offset of the required Priority field in this register ism MOD 4, where:
— byte offset 0 refers to register bits [7:0]
— byte offset 1 refers to register bits [15:8]
— byte offset 2 refers to register bits [23:16]
— byte offset 3 refers to register bits [31:24].
distributor之Interrupt Priority Registers, GICD_IPRIORITYRn
标签：gic
原文地址：http://blog.csdn.net/lixiaojie1012/article/details/40023717
