Timing device
A timing method and a timing device are disclosed. A Gray code count output may be obtained by performing a Gray code count on a basic clock. Then m number of sub-clocks may be obtained by separately performing a phase shift on a least significant bit output of the Gray code count output, where a phase difference φ between each of the m number of sub-clocks and the least significant bit output may satisfy: φ=n×α and φ≠90°, 180° may be divisible by α with no remainder, and n may be an integer greater than 0 and less than 180°/α. If 90° is divisible by α with no remainder, m=180/α−2; and if 90° is divisible by α with a remainder, m=180/α−1. When a predetermined event occurs, a timing result of the predetermined event may be obtained according to the Gray code count output value, outputs of the m number of sub-clocks, a period of the basic clock, and the α.
1. A timing method, comprising:
obtaining a Gray code count output by performing a Gray code count on a basic clock;
obtaining m number of sub-clocks by separately performing a phase shift on a least significant bit output of the Gray code count output, wherein a phase difference φ between each of the m number of sub-clocks and the least significant bit output satisfies: φ=n×α and φ≠90°, wherein, 180° is divisible by α with no remainder, and n is an integer greater than 0 and less than 180°/α;
when 90° is divisible by α with no remainder, m=180/α−2,
when 90° is divisible by α with a remainder, m=180/α−1; and
obtaining a timing result of a predetermined event according to the Gray code count output value, outputs of the m number of sub-clocks, a period of the basic clock, and the α when the predetermined event occurs.
2. The method according to claim 1 , wherein obtaining the timing result comprises:
obtaining a sub-clock count value; and
determining the timing result according to a formula as follows:
( B× 90°/α+ X )×Δ t;
wherein B is a Gray code count output value,
X is the sub-clock count value,
when a remainder obtained through dividing B by 4 is 0, X is equal to a number of sub-clocks with a high-level output among the m number of sub-clocks,
when the remainder obtained through dividing B by 4 is 1, X is equal to a difference between the number of sub-clocks with the high-level output among the m number of sub-clocks and i,
when the remainder obtained through dividing B by 4 is 2, X is equal to a difference between a product of 2×i and the number of sub-clocks with the high-level output among the m number of sub-clocks,
when the remainder obtained through dividing B by 4 is 3, X is equal to a difference between i and the number of sub-clocks with the high-level output among the m number of sub-clocks,
i is a smallest integer greater than or equal to 90°/α−1,
Δt=t 0 ×α/90°, and
t 0 is the period of the basic clock.
3. The method according to claim 2 , wherein obtaining the sub-clock count value X comprises:
obtaining a remainder through dividing the Gray code count output value B by 4;
when the remainder is 0, taking the number of sub-clocks with the high-level output among the m number of sub-clocks as the sub-clock count value X;
when the remainder is 1, taking the number of sub-clocks with the high-level output among a second set of m number of sub-clocks as the sub-clock count value X, wherein the second set of m number of sub-clocks are generated by shifting the outputs of the m number of sub-clocks to the right by i number of bits;
if the remainder is 2, taking the number of sub-clocks with the high-level output among a third set of m number of sub-clocks as the sub-clock count value X, wherein the third set of m number of sub-clocks are generated by inverting the outputs of the m number of sub-clocks; and
if the remainder is 3, taking the number of sub-clocks with the high-level output among a fourth set of m number of sub-clocks as the sub-clock count value X, wherein the fourth set of m number of sub-clocks are generated by inverting the outputs of the m number of sub-clocks and then shifting inverted outputs of the m number of sub-clocks to the right by i number of bits.
4. The method according to claim 2 , wherein obtaining the sub-clock count value X comprises:
obtaining the sub-clock count value by searching a lookup table,
wherein the lookup table comprises the sub-clock count value X and the Gray code count output value.
5. The method according to claim 1 , wherein obtaining the Gray code count output by performing the Gray code count on the basic clock comprises:
obtaining an original binary count output by performing an original binary count on the basic clock; and
converting the original binary count output into the Gray code count output.
6. The method according to claim 1 , wherein obtaining the Gray code count output by performing the Gray code count on the basic clock comprises:
obtaining the Gray code count output by performing a frequency division and a delay on the basic clock.
7. A timing device, comprising:
a count module configured to obtain a Gray code count output by performing a Gray code count on a basic clock;
m number of sub-clock modules respectively configured to obtain a sub-clock by performing a phase shift on a least significant bit output of the Gray code count output, wherein a phase difference φ between each of the m number of sub-clocks and the least significant bit output satisfies: φ=n×α and φ≠90°, wherein 180° is divisible by α with no remainder, and n is an integer greater than 0 and less than 180°/α;
when 90° is divisible by a with no remainder, m=180/α−2,
when 90° is divisible by a with no remainder, m=180/α−1;
a latch module configured to latch the Gray code count output and outputs of m number of sub-clocks obtained by the m number of sub-clock modules when a predetermined event occurs; and
a timing module configured to obtain a timing result of the predetermined event according to the Gray code count output value, outputs of the m number of sub-clocks, a period of the basic clock, and the α.
8. The timing device according to claim 7 , wherein the timing result comprises:
( B× 90°/α+ X )×Δ t;
wherein B is a Gray code count output value,
X is a sub-clock count value,
when a remainder obtained through dividing B by 4 is 0, X is equal to a number of sub-clocks with a high-level output among the m number of sub-clocks,
when the remainder obtained through dividing B by 4 is 1, X is equal to a difference between the number of sub-clocks with the high-level output among the m number of sub-clocks and i,
when the remainder obtained through dividing B by 4 is 2, X is equal to a difference between a product of 2×i and the number of sub-clocks with the high-level output among the m number of sub-clocks,
when the remainder obtained through dividing B by 4 is 3, X is equal to a difference between i and the number of sub-clocks with the high-level output among the m number of sub-clocks,
i is a smallest integer greater than or equal to 90°/α−1,
Δt=t 0 ×α/90°, and
t 0 , is the period of the basic clock.
9. The timing device according to claim 8 , wherein the timing module is configured to:
obtain a remainder through dividing the Gray code count output value B by 4;
when the remainder is 0, take the number of sub-clocks with the high-level output among the m number of sub-clocks i as the sub-clock count value X;
when the remainder is 1, take the number of sub-clocks with the high-level output among a second set of m number of sub-clocks as the sub-clock count value X, wherein the second set of m number of sub-clocks are generated by shifting the outputs of the m number of sub-clocks to the right by i number of bits;
when the remainder is 2, take the number of sub-clocks with the high-level output among a third set of m number of sub-clocks as the sub-clock count value X, wherein the third set of m number of sub-clocks are generated by inverting the outputs of the m number of sub-clocks; and
when the remainder is 3, take the number of sub-clocks with the high-level output among a fourth set of m number of sub-clocks as the sub-clock count value X, wherein the fourth set of m number of sub-clocks are generated by inverting the outputs of the m number of sub-clocks and then shifting inverted outputs of the m number of sub-clocks to the right by i number of bits.
10. The timing device according to claim 8 , wherein the timing module obtains the sub-clock count value X by searching a lookup table, wherein the lookup table comprises the sub-clock count value X and the Gray code count output value.
11. The timing device according to claim 7 , wherein the timing module comprises:
a count sub-module configured to obtain an original binary count output by performing an original binary count on the basic clock; and
a conversion sub-module configured to convert the original binary count output into the Gray code count output.
12. The timing device according to claim 7 , wherein the timing module comprises:
a frequency division and delay sub-module configure to obtain the Gray code count output by performing a frequency division and a delay on the basic clock.