Datasheet

// vPUKCL_Process() is a macro command,
// and then calls the library...
vPUKCL_Process(Comp,pvPUKCLParam);
if (PUKCL(u2Status) == PUKCL_OK)
{
// The COMPARE has been executed correctly
// CarryOut, Zero ... are available
... = PUKCL(Specific).CarryOut;
... = PUKCL(Specific).Zero;
}
else // Manage the error
43.3.4.8.6 Constraints
The following conditions must be avoided to ensure that the service works correctly:
• nu1XBase or nu1YBase are not aligned on 32-bit boundaries
• {nu1XBase, u2XLength} or {nu1YLength, u2YLength} are not in Crypto RAM
• u2XLength or u2YLength is either: < 4, > 0xffc or not a 32-bit length or u2XLength >u2YLength
43.3.4.8.7 Status Returned Values
Table 43-24. Comp Service Return Codes
Returned Status Importance Meaning
PUKCL_OK – Service functioned correctly
43.3.4.9 Full Multiply
43.3.4.9.1 Purpose
The purpose of this service is to multiply two large numbers, X and Y, and optionally accumulate/subtract
from a third large number, Z, returning the result, R.
The available options are as follows:
• Work in the GF(2
n
) field or in the standard arithmetic field
• Add of a supplemental CarryOperand
• Overlap of the operands is possible, taking into account some constraints
• Modular Reduction of the computation result (see 43.3.5.1 Modular Reduction)
43.3.4.9.2 How to Use the Service
43.3.4.9.3 Description
This service provides the following (if not computing a modular reduction of the result):
R = [Z] ± (X × Y + CarryOperand)
Or (if computing a modular reduction of the result):
R = ([Z] ± (X × Y + CarryOperand))mod N
The service name for this operation is Fmult.
In these computations, the following data has to be provided:
• R the result (pointed by {nu1RBase,u2Xlength +u2YLength})
• X one input number or GF(2
n
) polynomial (pointed by{nu1XBase,u2XLength})
• Y one input number or GF(2
n
) polynomial (pointed by{nu1YBase,u2YLength})
• Z one optional input number or GF(2n) polynomial (pointed by {nu1ZBase,u2Xlength +u2YLength})
SAM D5x/E5x Family Data Sheet
Public Key Cryptography Controller (PUKCC)
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1464