There are no Foreign Keys because this database is used read only, and the integrity is already assured as it is derived from a CMSIS-SVD.

sqlite> .schema

CREATE TABLE peripheral(
name TEXT PRIMARY KEY NOT NULL,
description TEXT
);

CREATE TABLE register(
peripheral_name TEXT NOT NULL,
name TEXT NOT NULL,
address TEXT,
resetValue TEXT,
access TEXT,
description TEXT,
PRIMARY KEY (peripheral_name, name));

CREATE TABLE field(
peripheral_name TEXT NOT NULL,register_name TEXT NOT NULL,name TEXT NOT NULL,
bitWidth NUMERIC,
bitOffset NUMERIC,
description TEXT
);