Fairchild CAM/CMOS-2K.LS user manual Mode 2 ExSync Synchronization

Figure 3.4.2 -- Mode 2: ExSync Synchronization

...gives the user asynchronous hardware control over initiation of the camera readout cycle

and over termination of the line period...

...separately gives the user asynchronous hardware control

			tLinePeriod
	n				n+1
>tMinSync		tReset2		tIntegration

tHold

ExSync

Camera Input

LineValid

Camera Output

	tReadout
	2048 Clock Cycles
tXFR	Data Camera Output

1 2 3 1023 1024

Strobe Camera Output

Line Valid Camera Output

Notes specific to this mode

1Unlike Freerunning mode, the user triggers (separately) both the CAM/CMOS - 2K.LS readout cycle, and the CAM/CMOS - 2K.LS reset-&-integration cycle. All of the modes other than Freerunning mode allow the user to do this

2The user initiates a readout cycle by taking ExSync low as shown above. Readout actually begins a time

"tXFR" after ExSync is taken low, and lasts 2048 clock cycles

3The user can read data from the CAM/CMOS - 2K.LS while LineValid is high as shown above and explained in Figure 3.4.1

4The reset-&-integration cycle to be read out in the next period "n+1" is initiated by ExSync returning high;

integration begins when reset is complete a time "tReset" after ExSync goes high, and continues

for the remainder of "tLinePeriod". The user can therefore shorten integration time by increasing "tHold" above

5The line period is set by the user by returning ExSync low, thereby initiating the next "n+1th" readout cycle

6The minimum time that ExSync can be held low is "tMinSync" as shown above

7Integration is cut off when the user takes ExSync low again as shown in the waveforms above

8The line period must be greater than or equal to "tReadout" plus tXfr", which sets maximum line rate to 50K lines/sec

9If the user brings the ExSync Camera Input low prior to "tXFR" + "tReadout" after ExSync goes low, then the CAM/CMOS 2K.LS delays initiation of the "n+1th" readout cycle until "tReadout"+ "tXFR" has elapsed after ExSync last went low

Fairchild Imaging • CAM/CMOS-2K.LS Line Scan Camera User’s Manual • Rev C• 22 of 42