Table 2.

State by state description of the PC, mCPLD, and mDSP interaction.

State	Description
Standby	mDSP is idle waiting for a signal from the host computer.
	mCPLD is idle waiting for a signal from the mDSP.
System parameters	1. mDSP receives CMD:01 from the host computer telling it to go into the System Parameters state.
	2. The host computer sends the number of sources, detectors, and wavelengths to the mDSP.
	3. mDSP returns to Standby.
	*mCPLD remains in Standby.
Gain Bit	1. mDSP receives CMD:10 from the host computer telling it to go into the Gain Bit download state.
	2. PC sends the gain bits for each source-detector pair.
	3. mDSP tells the mCPLD to go into Gain Bit state.
	4. mDSP sends the mCPLD the # of sources, detectors, wavelengths.
	5. mDSP sends the gain bits through the mCPLD to the detection boards while the mCPLD sends out control signals to the Gain Bit Shift Registers and FIFOs.
	6. mDSP and mCPLD return to Standby.
Imaging	1. mDSP receives CMD:11 from the host computer telling it to acquire one frame.
	2. mDSP tells mCPLD to go into Imaging State.
	3. mCPLD tells the optical switch to move to the next position. Updates the gain bits by reading from the detection board FIFOs. Waits for the TIMER signal from mDSP.
	4. DSP counts to 7 ms and then signals TIMER to mCPLD. During that time, it also runs the lock-in detection and sends data from previous source back to the PC.
	5. mCPLD acquires 150 samples from all detectors.
	6. mDSP receives data from the ADC. Returns to step 3 until all sources and wavelength sets are acquired.
	7. mDSP and mCPLD return to Standby.