ADNS-3090 Datasheet, PDF (34/38 Pages) Pixart Imaging Inc. – High-Performance Optical Mouse Sensor

PixArt Imaging Inc.
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Frame_Period_Max_Bound_Lower
Access: Read/Write
Bit
7
6
Field
FBm₇
FBm₆
Address: 0x19
Reset Value: 0xE0
5
4
FBm₅
FBm₄
3
FBm₃
2
FBm₂
1
FBm₁
0
FBm₀
Frame_Period_Max_Bound_Upper
Access: Read/Write
Bit
Field
7
FBm₁₅
6
FBm₁₄
Address: 0x1A
Reset Value: 0x2E
5
FBm₁₃
4
FBm₁₂
3
FBm₁₁
2
FBm₁₀
1
FBm₉
0
FBm₈
Data Type: 16-bit unsigned integer.
USAGE: This value sets the maximum frame period (the MINIMUM frame rate) which may be selected by the automatic
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
implement 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.
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PixArt Imaging Inc.
E-mail: [e-mail]
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