Silicon Valley nobility arrived at Stanford University on Sunday to pay tribute to revered Apple co-founder Steve Jobs.

Security teams from Apple and Stanford along with local police officers cordoned off the main quad on campus, only letting pass those with invitations to the private event.

Somberly attired men and women were directed to the university chapel for the Jobs memorial, and candles lined a path leading from the small church to a museum where a soiree was to be held after the ceremony.

Responses to invitations were directed to Emerson Collective, a philanthropy founded by the Apple co-founder's wife, Laurene Powell Jobs.

Amid global mourning for the death of the man behind iPhones, iPods, iPads, and Macintosh computers, California Governor Jerry Brown declared Sunday as "Steve Jobs Day" in the western US state.

"In his life and work, Steve Jobs embodied the California dream," Brown said in a statement.

"To call him influential would be an understatement.... His innovations transformed an industry, and the products he conceived and shepherded to market have changed the way the entire world communicates."

Jobs died on October 5 at the age of 56 after a years-long battle with cancer. He was buried in a private ceremony at a non-denominational cemetery three days later.

Jobs was also to be honored during an October 19 memorial for Apple employees at the company's headquarters in Cupertino, California.

"We are planning a celebration of Steve's extraordinary life for Apple employees that will take place soon," Apple chief executive Tim Cook said in a statement released the day Jobs died.

Apple has not indicated plans for a public memorial for Jobs, but people have paid tribute to him with flowers, candles, messages and more outside his home, the company headquarters and Apple retail stores around the world.

Jobs was a "uniquely Californian visionary. He epitomized the spirit of a state that an eager world watches to see what will come next," Brown said in his proclamation.