Device Certificate Service

Fetches the device’s Supply Chain Assurance Certificate from pNVM. The certificate data is stored as a 1024-bit entity but the actual certificate size may be smaller. Any excess bytes should be discarded by the user.

The device validates the certificate by checking its signature using the Microchip public key, MCPK. In addition:

The certificate DSN is checked against the device's serial number (DSN).
The certificate public key is checked by recalculating the value using factory key and comparing against the certificate.

In the event of an error, the certificate content is still returned for inspection.

Table 1. Design Certificate Service Request
System Service Descriptor Bit Field	Value	Description
15:7	MBOXADDR[10:2]	Mailbox address. See Table 2.
6:0	03H	Design Certificate service command.

The following table lists the Design Certificate Service mailbox format.

Table 2. Design Certificate Mailbox Format
Offset	Length (bytes)	Parameter	Direction	Description
0	1024	CERTIFICATE	Output	Device Certificate