34

Bit

7

6

5

4

3

2

1

0

Field

Bit

7654

32

1

0

Field

Frame_Period_Max_Bound_Lower

Address: 0x19

Access: Read/Write

Reset Value: 0xE0

Frame_Period_Max_Bound_Upper

Address: 0x1A

Access: Read/Write

Reset Value: 0x2E

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.

Frames/second

Counts

Frame_Period

Decimal

Hex

Upper

Lower

6469

3,710

OE7E

OE

7E

5000

4,800

12C0

12

C0

3000

8,000

1F40

1F

40

2000

12,000

2EE0

2E

E0

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PixArt Imaging Inc.

PixArt Imaging Inc.