This article contains information about the PIN caching mode for Nexus Personal Desktop Client.
...
When Personal Desktop Client is run in PIN caching mode, it is possible to cache PIN codes in the PKCS #11 Cryptographic Token Interface Base Specification Version 2.40 and the Smart Card Minidrivers (Windows only) modules. Personal Desktop Client can also run in PIN non-caching mode. Then no PIN caching will take place.
PIN caching applies to all tokens; both smart card and software tokens.
...