Datasheet

43.3.6.2.4 Parameters Definition
Table 43-68. ZpEccAddFast Service Parameters
Parameter Type Direction Location Data Length Before
Executing the
Service
After Executing
the Service
nu1ModBase nu1 I Crypto
RAM
u2ModLength + 4 Base of Modulus
P
Base of
Modulus P
nu1CnsBase nu1 I Crypto
RAM
u2ModLength + 8 Base of Cns Base of Cns
u2ModLength u2 I – – Length of
modulo
Length of
modulo
nu1PointABase nu1 I/O Crypto
RAM
3*u2ModLength
+ 12
Input point A
(projective
coordinates)
Resulting point
C (projective
coordinates)
nu1PointBBase nu1 I Crypto
RAM
3*u2ModLength
+ 12
Input point B
(projective
coordinates)
Input point B
nu1Workspace nu1 I Crypto
RAM
5*u2ModLength
+ 32
– Corrupted
workspace
43.3.6.2.5 Code Example
PUKCL_PARAM PUKCLParam;
PPUKCL_PARAM pvPUKCLParam = &PUKCLParam;
PUKCL (u2Option) = 0;
PUKCL _ZpEccAdd(nu1ModBase) = <Base of the ram location of P>;
PUKCL _ZpEccAdd(nu1CnsBase) = <Base of the ram location of Cns>;
PUKCL _ZpEccAdd(u2ModLength) = <Byte length of P>;
PUKCL _ZpEccAdd(nu1PointABase) = <Base of the ram location of the A point>;
PUKCL _ZpEccAdd(nu1PointBBase) = <Base of the ram location of the B point>;
PUKCL _ZpEccAdd(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(ZpEccAddFast,&PUKCLParam);
if (PUKCL (u2Status) == PUKCL_OK)
{
...
}
else // Manage the error
43.3.6.2.6 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, nu1PointBBase, nu1Workspace are not aligned on 32-
bit boundaries
• {nu1ModBase, u2ModLength + 4}, {nu1CnsBase, u2ModLength + 8}, {nu1PointABase,
3*u2ModLength + 12}, {nu1PointBBase, 3*u2ModLength + 12}, {nu1Workspace,
<WorkspaceLength>} are not in Crypto RAM
• u2ModLength is either: < 12, > 0xffc or not a 32-bit length
SAM D5x/E5x Family Data Sheet
Public Key Cryptography Controller (PUKCC)
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1511