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2.0 Software
2.1
Launching the Program
To start the software, go to the Windows ‘Start - Programs’ menu and select ‘LM87 – LM87Eval’.
2.2 Operation
•
The software provides most of the commonly used information on the main panel. A series of menus
are used to provide the following additional functions:
•
File – Provides ability to load and save communication and watchdog limit settings. Also provides exit
mechanism from the software.
•
Communication Settings – Communications port and SMBus address settings.
•
Registers – Provides access to all LM87 registers.
•
Help – The LM87 datasheet, this manual and the evaluation board schematic can be accessed.
2.3
Initial Settings
When first launched, the software is configured for the following default communication settings:
•
Parallel printer port address = 0x3F8h
•
LM87 SMBus address bits = 00b
If different settings are required, adjust them through the Communication Settings menu. These alternate
communication settings can be saved to disk by using the File-Save Communication Settings menu choice.
Previously saved Communication Settings can be loaded via the File-Load Communication Settings menu
item.
2.4
Power On
Click on the “DUT Power Off” button on the screen. The button text will change to “DUT Power On” and
power will be applied to the LM87 through the parallel port. The board is now ready for communication.
At this point, the state of all registers in the LM87 can be read. The Values, Limit Settings and Status Bits
displayed in the main panel can be updated by clicking on the button labeled “Get All Values”.
2.5
Configuration Registers
Additional Configuration and Control registers are accessed by selecting the menu “Registers”. These
additional choices provide the following functions:
•
Channel Mode Register > This configures the device for the alternate input functions.
•
Configuration Register 1 > This is used to configure basic features.
•
Configuration Register 2 > This is used to configure more advanced features.
•
DAC Setting Register > This allows easy adjustment of the fan drive DAC.
•
VID Reading > This allows all 5 VID bits to be observed.
•
User Choice > This panel provides Read/Write access to any register in the device.
•
Test Register > Bit 0 allows the LM87 to be placed in the low power standby mode.
2.6
Starting Conversions
The LM87 default wakeup state is powered up, but NOT converting. To start Analog to Digital
conversions, Configuration Register 1 must be adjusted. Open the Configuration Register 1 menu panel.
The initial setting should be all 0’s except Bit 3. To start conversions, change Bit 3 to 0 and set Bit 0 to 1.
To change the state of any bit, simply click in the white bit position box and the value will change (The
register is written and read back every time a bit is changed). Once the LM87 is converting, return to the
main panel and click on “Get All Values” again. This will update all of the displayed readings with the
newly converted values.