
36
Frame_Period_Max_Bound_Lower
Access: Read/Write
Address: 0x19
Default Value: 0x90
Bit
Field
7
6
5
4
3
2
1
0
FBM
7
FBM
6
FBM
5
FBM
4
FBM
3
FBM
2
FBM
1
FBM
0
Frame_Period_Max_Bound_Upper
Access: Read/Write
Address: 0x1A
Default Value: 0x65
Bit
Field
7
6
5
4
3
2
1
0
FBM
15
FBM
14
FBM
13
FBM
13
FBM
11
FBM
10
FBM
9
FBM
8
Data Type
:
16-bit unsigned integer.
USAGE: This value sets the maximum frame period (the MINIMUM frame rate) which may be selected by the auto-
matic frame rate control, or sets the actual frame period when operating in manual mode. Units are clock cycles. The
formula is
Frame Rate = Clock Frequency / Register value
To read from the registers, read Upper first followed by Lower. To write to the registers, write Lower first, followed by
Upper. To set the frame rate manually, disable automatic frame rate mode via the Extended_Config register and write
the desired count value to these registers.
Writing to the Frame_Period_Max_Bound_Upper and Lower registers also activates any new values in the following
registers:
·
Frame_Period_Max_Bound_Upper and Lower
·
Frame_Period_Min_Bound_Upper and Lower
·
Shutter_Max_Bound_Upper and Lower
Any data written to these registers will be saved but will not take effect until the write to the Frame_Period_Max_
Bound_Upper and Lower is complete. After writing to this register, two complete frame times are required to imple-
ment the new settings. Writing to any of the above registers before the implementation is complete may put the chip
into an undefined state requiring a reset. The “Busy” bit in the Extended_Config register may be used in lieu of a timer
to determine when it is safe to write. See the Extended_Config register for more details.
The following table lists some Frame_Period values for popular frame rates (clock rate = 24MHz). In addition, the three
bound registers must also follow this rule when set to non-default values:
Frame_Period_Max_Bound
≥
Frame_Period_Min_Bound + Shutter_Max_Bound.
Frames/second
Counts
Frame_Period
Decimal
Hex
Upper
Lower
7080
3,390
0D3E
0D
3E
5000
4,800
12C0
12
C0
3000
8,000
1F40
1F
40
2000
12,000
2EE0
2E
E0