
30
Shutter_Lower
Address: 0x0e
Access: Read
Reset Value: 0x85
System Test: This test is initiated via the Configuration_Bits register. It performs several tests to verify that the hardware
is functioning correctly. Perform a hardware reset just prior to running the test. SROM contents and register settings
will be lost.
SROM CRC Test: Performs a CRC on the SROM contents. The test is initiated by writing a particular value to the
SROM_Enable register.
Bit
7
6
5
4
3
2
1
0
Field
DO
7
DO
6
DO
5
DO
4
DO
3
DO
2
DO
1
DO
0
Bit
7
6
5
4
3
2
1
0
Field
DO
15
DO
14
DO
13
DO
12
DO
11
DO
10
DO
9
DO
8
Data_Out_Upper
Data_Out_Lower
System test results:
0x1B
0xBF
SROM CRC Test Result:
0xBE
0xEF
Shutter_Upper
Address: 0x0f
Access: Read
Reset Value: 0x00
Data Type: Sixteen bit unsigned integer.
USAGE: Units are clock cycles. Read Shutter_Upper first, then Shutter_Lower. They should be read consecutively. The
shutter is adjusted to keep the average and maximum pixel values within normal operating ranges. The shutter value
is checked and automatically adjusted to a new value if needed on every frame when operating in default mode.
When the shutter adjusts, it changes by ± 1/16 of the current value. The shutter value can be set manually by setting
the AGC mode to Disable using the Extended_Config register and writing to the Shutter_Maximum_Bound registers.
Because the automatic frame rate feature is related to shutter value. It may also be appropriate to enable the Fixed
Frame Rate mode using the Extended_Config register.
Shown below is a graph of 250 sequentially acquired shutter values, while the sensor was moved slowly over white
paper.
Bit
7
6
5
4
3
2
1
0
Field
S
7
S
6
S
5
S
4
S
3
S
2
S
1
S
0
Bit
7
6
5
4
3
2
1
0
Field
S
15
S
14
S
13
S
12
S
11
S
10
S
9
S
8
Data_Out_Lower
Address: 0x0c
Access: Read
Reset Value: Undefined
Data_Out_Upper
Address: 0x0d
Access: Read
Reset Value: Undefined
Data Type: Sixteen bit word.
USAGE: Data in these registers come from the system self test or the SROM CRC test. The data can be read out 0x0d,
or 0x0d first, then 0x0c.