Datasheet

...........continued
Parameter Type Direction Location Data Length Before
Executing the
Service
After
Executing the
Service
nu1PointBase nu1 I Crypto RAM 3*u2ModLength
+ 12
Input point Resulting point
nu1RandomBase nu1 I Crypto RAM u2ModLength + 4 Random Corrupted
nu1Workspace nu1 I Crypto RAM 3*u2ModLength
+ 28
– Workspace
43.3.7.7.5 Code Example
PUKCL_PARAM PUKCLParam;
PPUKCL_PARAM pvPUKCLParam = &PUKCLParam;
// ! The Random Number Generator must be initialized and started
// ! following the directives given for the RNG on the chip
PUKCL (u2Option) = 0;
// Depending on the option specified, not all fields should be filled
PUKCL _GF2NEcRandomiseCoordinate(nu1ModBase) = <Base of the ram location of P>;
PUKCL _GF2NEcRandomiseCoordinate(u2ModLength) = <Byte length of P>;
PUKCL _GF2NEcRandomiseCoordinate(nu1CnsBase) = <Base of the ram location of Cns>;
PUKCL_GF2NEcRandomiseCoordinate(nu1RandomBase) = <Base of the ram location where the the rng
is stored>;
PUKCL _GF2NEcRandomiseCoordinate(nu1PointBase) = <Base of the ram location of the point>;
PUKCL _GF2NEcRandomiseCoordinate(nu1Workspace) =
<Base of the ram location of the workspace>;
...
// vPUKCL_Process() is a macro command, which populates the service name
// and then calls the library...
vPUKCL_Process(GF2NEcRandomiseCoordinate,&PUKCLParam);
if (PUKCL (u2Status) == PUKCL_OK)
{
...
}
else // Manage the error
43.3.7.7.6 Constraints
No overlapping between either input and output are allowed. The following conditions must be avoided to
ensure that the service works correctly:
• nu1ModBase, nu1CnsBase, nu1PointABase, nu1RandomBase, nu1Workspace are not aligned on
32-bit boundaries
• {nu1ModBase, u2ModLength + 4}, {nu1CnsBase, u2ModLength + 8}, {nu1PointABase,
3*u2ModLength + 12}, {nu1RandomBase, u2ModLength + 4}, {nu1Workspace, <WorkspaceLength>}
are not in Crypto RAM
• u2ModLength is either: < 12, > 0xffc or not a 32-bit length
• All overlapping between {nu1ModBase, u2ModLength + 4}, {nu1CnsBase, u2ModLength + 8},
{nu1PointABase, 3*u2ModLength + 12}, {nu1RandomBase, u2ModLength + 4} and {nu1Workspace,
3*u2ModLength + 28}
SAM D5x/E5x Family Data Sheet
Public Key Cryptography Controller (PUKCC)
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1557