Specifications

11.2.36 Test 70: Maxim 1617 Thermal Sensor Test
This BIST checks the operation of the Maxim 1617 Thermal Sensor.
This test consists of a number of sub-tests, which can be selected via a command line
parameter. If the BIST is invoked without parameters, only basic diagnostics and CPU over-heat
are checked. The CPU over-heat temperature is preset to 95°C. The following sub-tests are
available; (D) indicates a test run by default; (B) indicates a test which performs a basic
functionality test first.
0 Temperature readout (B) (D)
1 Set alarms (B)
2 Change update frequency (B)
3 Full readout
11.2.36.1 Basic Functionality
The basic functionality tests perform the following checks on the Maxim 1617 Thermal Sensor:
The CPU sensor is not open-circuit.
The CPU sensor is not short-circuit. Should this error occur, the CPU sensor will always read
0°C.
The CPU sensor is not connected to Vcc. Should this error occur both the ambient and CPU
sensors will always read 127°C.
11.2.36.2 Temperature Readout
This sub-test will perform a basic functionality test, display the current temperature readings and
finally check that the CPU has not breached the 95°C alarm. Should this alarm be triggered or
basic diagnostics fail, the BIST will report an error.
11.2.36.3 Set Alarms
This option allows the user to program the four alarms: Ambient Low; Ambient High, CPU Low
and CPU high. The range on each alarm is –65°C to 127°C. These temperatures may be
specified as BIST parameters in the order above.
As BISTs do not provide support for the minus sign, negative numbers should be entered by
replacing the “-“ symbol with a “9” (I.e. “-34” becomes “934”). 0°C is valid but, for the CPU
sensor, may be confused with a short-circuit. 127°C is valid but, on both sensors, may be
confused with a short to Vcc.
11-20 VP 110/01x
VSA Mode Diagnostics