1. A method of operating a programmable device having a plurality of configuration memory cells and a processing core, the method comprising:
defining a don’t care set of configuration memory cells in the plurality of configuration memory cells; and
using the don’t care set of configuration memory cells as readwrite memory for the processing core.
2. The method of operating a programmable device of claim 1, further comprising configuring a portion of the programmable device as the processing core.
3. The method of operating a programmable device of claim 1, wherein the don’t care set of configuration memory cells includes configuration memory cells associated with an unused portion of the programmable device.
4. The method of operating a programmable device of claim 1, wherein the don’t care set of configuration memory cells includes configuration memory cells associated with a partially configured configurable logic block.
5. The method of operating a programmable device of claim 1, further comprising configuring a portion of the programmable device as a memory management unit.
6. The method of operating a programmable device of claim 1, wherein the defining the don’t care set of configuration memory cells comprises:
defining a care set of configuration memory cells; and
defining configuration memory cells not included in the care set of configuration memory cells as the don’t care set of configuration memory cells.
7. The method of operating a programmable device of claim 1, wherein the using the don’t care set of configuration memory cells as readwrite memory for the processing core further comprises:
reading a frame of data from the don’t care set of configuration memory cells;
modifying a portion of the frame of data; and
writing the frame of data to the don’t care set of configuration memory cells.
8. The method of operating a programmable device of claim 1, further comprising storing predetermined user data in a subset of the don’t care set of configuration memory cells.
9. The method of operating a programmable device of claim 8, wherein the storing predetermined user data in the subset of the don’t care set of configuration memory cells comprises writing the predetermined user data into the subset of the don’t care set of configuration memory cells from a configuration bitstream.
10. The method of operating a programmable device of claim 8, wherein the subset of the don’t care set of configuration memory cells is treated as read-only memory.
11. A method of operating a programmable device having a plurality of configuration memory cells and a processing core, the method comprising:
defining a don’t care set of configuration memory cells in the plurality of configuration memory cells; and
storing predetermined user data in a subset of the don’t care set of configuration memory cells.
12. The method of operating a programmable device of claim 11, further comprising configuring a portion of the programmable device as the processing core.
13. The method of operating a programmable device of claim 11, wherein the don’t care set of configuration memory cells includes configuration memory cells associated with an unused portion of the programmable device.
14. The method of operating a programmable device of claim 11, wherein the don’t care set of configuration memory cells includes configuration memory cells associated with a partially configured configurable logic block.
15. The method of operating a programmable device of claim 11, wherein the defining the don’t care set of configuration memory cells comprises:
defining a care set of configuration memory cells; and
defining configuration memory cells not included in the care set of configuration memory cells as the don’t care set of configuration memory cells.
16. The method of operating a programmable device of claim 11, wherein the storing predetermined user data in the subset of the don’t care set of configuration memory cells comprises writing the predetermined user data into the subset of the don’t care set of configuration memory cells from a configuration bitstream.
17. The method of operating a programmable device of claim 11, wherein the subset of the don’t care set of configuration memory cells is treated as read-only memory.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An image forming apparatus comprising:
a pattern forming unit that forms a color-misalignment detection pattern on an image carrier;
a light-intensity detecting unit that detects the color-misalignment detection pattern formed on the image carrier by irradiating the image carrier with a light and detecting light intensity of a reflected light from the image carrier; and
a color-misalignment-amount detecting unit that detects an amount of a color misalignment of an image based on the light intensity of the reflected light detected by the light-intensity detecting unit, wherein
a spot of the light on the image carrier is elongated in a main-scanning direction.
2. The image forming apparatus according to claim 1, wherein the pattern forming unit forms the color-misalignment detection pattern in a plurality of rows within a length of the spot of the light in the main-scanning direction.
3. The image forming apparatus according to claim 1, wherein
the color-misalignment detection pattern includes a main-scanning-direction misalignment detection pattern for detecting a color misalignment in the main-scanning direction,
the pattern forming unit forms the main-scanning-direction misalignment detection pattern including a first pattern for a predetermined reference color and a second pattern for a non-reference color other than the reference color arranged being overlapped with each other on the image carrier,
a plurality of the first patterns and a plurality of the second patterns are arranged in the sub-scanning direction with different amounts of the color misalignment in the main-scanning direction, and
the light-intensity detecting unit detects the amount of the color misalignment in the main-scanning direction based on a variation in the light intensity caused by shifts of the reflected lights from the first pattern and the second pattern in the main-scanning direction, and
a length of the second pattern in the sub-scanning direction is shorter than a length of the spot in the sub-scanning direction.
4. The image forming apparatus according to claim 3, wherein
the length of the second pattern in the sub-scanning direction is shorter than the length of the spot sub-scanning, and
a length of the first pattern in the sub-scanning direction is longer than the length of the spot in the sub-scanning direction.
5. The image forming apparatus according to claim 1, wherein
the color-misalignment detection pattern includes a sub-scanning-direction misalignment detection pattern for detecting a color misalignment in a sub-scanning direction,
the pattern forming unit forms the sub-scanning-direction misalignment detection pattern including a first pattern for a predetermined reference color and a second pattern for a non-reference color other than the reference color arranged being overlapped with each other on the image carrier,
a plurality of the first patterns and a plurality of the second patterns are arranged in the sub-scanning direction with different amounts of the color misalignment in the sub-scanning direction, and
line widths of the first pattern and the second pattern in the sub-scanning direction are shorter than a length of the spot in the sub-scanning direction.
6. The image forming apparatus according to claim 1, wherein
the color-misalignment detection pattern includes a main-scanning-direction misalignment detection pattern for detecting a color misalignment in the main-scanning direction or a sub-scanning-direction misalignment detection pattern for detecting a color misalignment in a sub-scanning direction,
the pattern forming unit forms one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern including a first pattern for a predetermined reference color and a second pattern for a non-reference color other than the reference color arranged being overlapped with each other on the image carrier, and
the first pattern is formed without forming the second pattern in a specific region, and
the light-intensity detecting unit detects the amount of the color misalignment in one of the main-scanning direction and the sub-scanning direction based on a variation in the light intensity caused by shifts of the reflected lights from the first pattern and the second pattern in one of the main-scanning direction and the sub-scanning direction.
7. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by (Vmax-VBk)VBk is smaller than a preset determination value, where Vmax is a maximum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit and VBk is an output of the first pattern from the light-intensity detecting unit.
8. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by (Vmax-VBk)(VBk-V0) is smaller than a preset determination value, where Vmax is a maximum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit, VBk is an output of the first pattern from the light-intensity detecting unit, and V0 is an output without patterns from the light-intensity detecting unit.
9. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by (Vmax-VBk)(Vmin-VBk) is smaller than a preset determination value, where Vmax is a maximum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit, VBk is an output of the first pattern from the light-intensity detecting unit, and Vmin is a minimum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit.
10. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by (Vmin-VBk)VBk is larger than a preset determination value, where VBk is an output of the first pattern from the light-intensity detecting unit and Vmin is a minimum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit.
11. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by (Vmin-VBk)(VBk-V0) is larger than a preset determination value, where VBk is an output of the first pattern from the light-intensity detecting unit, Vmin is a minimum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit, and V0 is an output without patterns from the light-intensity detecting unit.
12. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by Vmax-Vmin is smaller than a preset determination value, where Vmax is a maximum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit and Vmin is a minimum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit.
13. The image forming apparatus according to claim 6, further comprising:
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when a value obtained by Vmax-VBk is smaller than a preset determination value, where Vmax is a maximum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit and VBk is an output of the first pattern from the light-intensity detecting unit.
14. The image forming apparatus according to claim 6, further comprising:
a storage unit that stores therein a plurality of determination conditions selected from
{(Vmax-VBk)VBk}<(determination value)
{(Vmax-VBk)(VBk-V0)}<(determination value)
{(Vmax-VBk)(Vmin-VBk)}<(determination value)
{(Vmin-VBk)VBk}>(determination value)
{(Vmin-VBk)(VBk-V0)}>(determination value)
(Vmax-Vmin)<(determination value)
(Vmax-VBk)<(determination value)
where Vmax is a maximum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit, Vmin is a minimum output of one of the main-scanning-direction misalignment detection pattern and the sub-scanning-direction misalignment detection pattern from the light-intensity detecting unit, VBk is an output of the first pattern from the light-intensity detecting unit, and V0 is an output without patterns from the light-intensity detecting unit; and
a determining unit that determines that there is a large color misalignment in one of the main-scanning direction and the sub-scanning direction when any one of values obtained by the determination conditions stored in the storage unit is satisfied.
15. The image forming apparatus according to claim 7, wherein a value of Vmax is an average value of the maximum output and a second maximum output from the light-intensity detecting unit.
16. The image forming apparatus according to claim 8, wherein a value of Vmax is an average value of the maximum output and a second maximum output from the light-intensity detecting unit.
17. The image forming apparatus according to claim 9, wherein a value of Vmax is an average value of the maximum output and a second maximum output from the light-intensity detecting unit.
18. The image forming apparatus according to claim 12, wherein a value of Vmax is an average value of the maximum output and a second maximum output from the light-intensity detecting unit.
19. The image forming apparatus according to claim 13, wherein a value of Vmax is an average value of the maximum output and a second maximum output from the light-intensity detecting unit.
20. The image forming apparatus according to claim 14, wherein a value of Vmax is an average value of the maximum output and a second maximum output from the light-intensity detecting unit.
21. An image forming method comprising:
forming a color-misalignment detection pattern on an image carrier;
detecting the color-misalignment detection pattern formed on the image carrier by irradiating the image carrier with a light and detecting light intensity of a reflected light from the image carrier; and
detecting an amount of a color misalignment of an image based on the light intensity of the reflected light, wherein
a spot of the light on the image carrier is elongated in a main-scanning direction.