
RM0453 Rev 2
719/1454
RM0453
Public key accelerator (PKA)
721
24.7.2 PKA
status
register (PKA_SR)
Address offset: 0x04
Reset value: 0x0000 0000
Bits 7:2 Reserved, must be kept at reset value.
Bit 1
START
: start the operation
Writing 1 to this bit starts the operation which is selected by MODE[5:0], using the operands
and data already written to the PKA RAM. This bit is always read as 0.
Note: START is ignored if PKA is busy.
Bit 0
EN
: PKA enable.
0: Disable PKA
1: Enable PKA
Note: When EN=0 PKA RAM can still be accessed by the application.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
ADDR
ERRF
RAM
ERRF
Res.
PROC
ENDF
BUSY
r
r
r
r
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Bits 31:21 Reserved, must be kept at reset value.
Bit 20
ADDRERRF
: Address error flag
0: No Address error
1: Address access is out of range (unmapped address)
This bit is cleared using ADDRERRFC bit in PKA_CLRFR.
Bit 19
RAMERRF
: PKA RAM error flag
0: No PKA RAM access error
1: An AHB access to the PKA RAM occurred while the PKA core was computing and using its
internal RAM (AHB PKA_RAM access are not allowed while PKA operation is in progress).
This bit is cleared using RAMERRFC bit in PKA_CLRFR.
Bit 18 Reserved, must be kept at reset value.
Bit 17
PROCENDF
: PKA End of Operation flag
0: Operation in progress
1: PKA operation is completed. This flag is set when the BUSY bit is deasserted.
Bit 16
BUSY
: PKA operation is in progress
This bit is set to 1 whenever START bit in the PKA_CR is set. It is automatically cleared when the
computation is complete, meaning that PKA RAM can be safely accessed and a new operation can
be started.
0: No operation is in progress (default)
1: An operation is in progress
If PKA is started with a wrong opcode the peripheral is busy for a couple of cycles, then it aborts
automatically the operation and go back to ready (BUSY bit is set to 0).
Bits 15:0 Reserved, must be kept at reset value.