Agilent Technologies 8453 Operator's Manual page 149

Theory of Operation
Firmware Description
Firmware Description
The firmware of the instrument comprises two parts. One part is used by the
MP 68332 processor on the SPM board, that is, to boot the instrument and
use the basic functions of the processor for memory control and input-output
control. The other part for the DSP on the SPM board is used to make the
instrument operate as a spectrophotometer.
Firmware updates of the instrument-specific part can be done by a download
procedure from the computer. Updates will be provided on flexible disk.
Resident Part of the Firmware
If the instrument is configured to stay in the resident part of the firmware, it
does not react as a spectrophotometer but uses only the basic functionality
of the microprocessor system. In this case the firmware is used to establish
the communication to the computer, that is, for data communication through
the GPIB, CAN and RS232 interfaces. For reseting the instrument that it stays
in the resident part of the firmware and forced cold start, see Chapter 6
"Interfacing".
Instrument-Specific Part of the Firmware
The instrument-specific part of the firmware is used to supervise:
• interface control for multicell transport, GPIO lines and APG remote,
• MIO board and accessory board control,
• internal events such as lamp turn-on cycle and shutter and filter
movements,
• diagnostic functions, and
• raw data conversion to absorbance.
Raw Data Conversion to Absorbance
The raw data flow (from the photodiode array) and conversion to absorbance
spectra with variance for each data point is a multiple-step process. This
process is outlined in this section
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