ICC_RPR_EL1, Interrupt Controller Running Priority Register
The ICC_RPR_EL1 characteristics are:
Purpose
Indicates the Running priority of the CPU interface.
Configuration
AArch64 System register ICC_RPR_EL1 performs the same function as AArch32 System register ICC_RPR.
Attributes
ICC_RPR_EL1 is a 64-bit register.
Field descriptions
The ICC_RPR_EL1 bit assignments are:
| 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 |
| RES0 | |||||||||||||||||||||||||||||||
| RES0 | Priority | ||||||||||||||||||||||||||||||
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Bits [63:8]
Reserved, RES0.
Priority, bits [7:0]
The current running priority on the CPU interface. This is the group priority of the current active interrupt.
If there are no active interrupts on the CPU interface, or all active interrupts have undergone a priority drop, the value returned is the Idle priority.
The priority returned is the group priority as if the BPR for the current Exception level and Security state was set to the minimum value of BPR for the number of implemented priority bits.
If 8 bits of priority are implemented the group priority is bits[7:1] of the priority.
Accessing the ICC_RPR_EL1
Software cannot determine the number of implemented priority bits from a read of this register.
Accesses to this register use the following encodings:
MRS <Xt>, ICC_RPR_EL1
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b000 | 0b1100 | 0b1011 | 0b011 |
if PSTATE.EL == EL0 then
UNDEFINED;
elsif PSTATE.EL == EL1 then
if ICC_SRE_EL1.SRE == '0' then
AArch64.SystemAccessTrap(EL1, 0x18);
elsif EL2Enabled() && !ELUsingAArch32(EL2) && ICH_HCR_EL2.TC == '1' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.FMO == '1' then
return ICV_RPR_EL1;
elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.IMO == '1' then
return ICV_RPR_EL1;
elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then
AArch64.SystemAccessTrap(EL3, 0x18);
else
return ICC_RPR_EL1;
elsif PSTATE.EL == EL2 then
if ICC_SRE_EL2.SRE == '0' then
AArch64.SystemAccessTrap(EL2, 0x18);
elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then
AArch64.SystemAccessTrap(EL3, 0x18);
else
return ICC_RPR_EL1;
elsif PSTATE.EL == EL3 then
if ICC_SRE_EL3.SRE == '0' then
AArch64.SystemAccessTrap(EL3, 0x18);
else
return ICC_RPR_EL1;