There have been some debate (even heated) about the reliability of smaller electronic devices in a EMP event.
From the report:
<div>However, an EMP would cause instantaneous and simulta-</div>
<div>neous loss of many technologies reliant on electrical power and computer circuit boards, such as cell phones and GPS devices.</div>
While many theorize the impacts to the devices mentioned above, the only people who have access to the technology to actually test is the DOE, DoD, and some national laboratories, likely at a classified level. The line above may have been a inadvertent disclosure by the DoD that cell phones and hand held GPS devices are susceptible to EMP.