Transmission and Reception Methods for a Binary Signal on a Serial Link

• US 20160164701A1
• Filed: 09/14/2015
• Published: 06/09/2016
• Est. Priority Date: 12/04/2014
• Status: Active Grant

• Current Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SAS (STMicroelectronics NV)
• Inventors: ARNAL, Christophe, Van Der Tuijn, Roland
• Granted Patent: US 10,122,552 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: H04B 10/0795 Performance monitoring; Measurement of transmission parameters
• CPC Class Codes: H04L 25/0262 Arrangements for detecting the data rate of an incoming signal

Abstract

A method can be used for transmission of at least one packet of at least one bit over a serial link capable of taking two different states respectively associated with the two possible logical values of the at least one transmitted bit. Starting from a transmission start time of the at least one bit and up to the expiration of a first portion of a bit time associated with the at least one bit, the link is placed in one of its states depending on the logical value of the at least one bit. Upon the expiration of the first portion of this bit time, a first additional transition is generated over the link so as to place the link in its other state up to the expiration of the bit time.

Claims

1. A method of transmitting a plurality of bits over a serial link that is capable of taking two different states respectively associated with two possible logical values of the transmitted bits, the method comprising:

starting from a transmission start time of a first bit and up to expiration of a first portion of a bit time associated with the first bit, placing the link in one of the two different states depending on the logical value of the first bit; and

upon expiration of the first portion of the bit time, generating a first additional transition over the link so as to place the link in the other one of the two different states up to an expiration of the bit time.

2. The method according to claim 1, wherein the first portion of the bit time is between 60% and 90% of the bit time.

3. The method according to claim 1, wherein the plurality of bits that form a packet and wherein transmission of a second bit begins at the expiration of the bit time associated with the first bit.

4. The method according to claim 3, wherein the bit time associated with the first bit of the packet is longer than a bit time associated with other bits of the packet and the bit times associated with the other bits of the packet may be determined, by a known relationship, from the bit time associated with the first bit of the packet.

5. The method according to claim 4, wherein the other bits are transmitted by placing the link in only one state for each bit, the state depending on the logical value of the bit being transmitted.

6. The method according to claim 3, wherein the bit time associated with all the bits of the packet are identical, or different for some of them but determinable by a known relationship, the method further comprising transmitting an other bit, the transmitting comprising:

starting from a transmission start time of the other bit and up to expiration of a period counted starting from the transmission start time of the first bit and equal to a sum of all of the bit times associated with earlier bits preceding the other bit and of a second portion of the bit time associated with the other bit, placing the link in one of the two different states depending on the logical value of the other bit; and

upon the expiration of the period, generating a second additional transition over the link so as to place the link in the other one of the two different states up to an expiration of the bit time associated with the other bit.

7. The method according to claim 6, wherein the first portion and the second portion are the same.

8. The method according to claim 6, wherein the first bit is the only earlier bit so that the period is equal to the bit time of the first bit.

9. The method according to claim 3, wherein steps of placing the link in one of the two different states and generating an additional transition over the link are performed for each bit of the packet, the transmission of a current bit, from a second bit up to a last bit, beginning at the expiration of the bit time associated with the latest preceding bit.

10. A processing unit configured for a plurality of bits over a serial link that is capable of taking two different states respectively associated with two possible logical values of the transmitted bits, the processing unit comprising a transmission processing unit configured to implement the method of claim 1.

11. A method for receiving a bit carried over a serial link that is capable of taking two different states that are associated with two possible logical values of the bit, the method comprising:

detecting a first transition between the two states of the link, the first transition occurring at a time after a reception start time of the bit; and

determining a first period separating the reception start time and the time of occurrence of the first transition, a reception end time of the bit being separated from the time of occurrence of the first transition by a first additional period that is equal to a first predetermined portion of the first period.

12. The method according to claim 11, wherein the first predetermined portion is between 10% and 70% of the first period.

13. The method according to claim 11, wherein the method comprises receiving a packet that comprises a plurality of bits, the bit being a first bit of the plurality of bits, the method further comprising receiving a second bit beginning at an expiration of the first additional period associated with the first bit.

14. The method according to claim 13, wherein the bit time associated with the first bit of the received packet is longer than the bit time associated with other bits of the packet, the method further comprising determining the bit time associated with the other bits from the bit time associated with the first bit of the received packet using a known relationship.

15. The method according to claim 14, wherein the other bits are received while in only one state for each bit, the state depending on the logical value of the bit being transmitted.

16. The method according to claim 13, wherein all the bits of the packet have the same bit time, or have different bit times for some of them that are determinable by a known relationship, the method further comprising receiving an other bit of the packet, the receiving comprising:

detecting an occurrence of a second transition between the two states of the link after a reception start time of the other bit; and

determining a second period separating the reception start time of the first bit and the time of occurrence of the second transition, the reception end time of the other bit being separated from the time of occurrence of the second transition by a second additional period that is equal to a second predetermined portion of the second period.

17. The method according to claim 16, wherein the first portion and the second portion are the same.

18. The method according to claim 13, further comprising receiving each of the other bits of the packet after receiving the first bit, wherein receiving each of the other bits includes detecting an additional transition after a reception start time of that bit.

19. A processing unit configured to receive a packet of bits carried over a serial link, the processing unit comprising a reception processing unit configured to implement the method according to claim 11.

20. A method of communicating using a serial link, the method comprising:

transmitting an initial start bit portion for a first time period, the start bit having a start bit time;

transmitting an additional start bit portion having a second time period, the additional start bit portion having an inverse value of the initial start bit portion and the start bit time being equal to the sum of the first time period and the second time period; and

after the start bit time, transmitting a plurality of useful bits, each of the useful bits have a useful bit time, the start bit time being longer than the useful bit time and being an integer multiple of the useful bit time.

21. The method according to claim 20, further comprising:

receiving the initial start bit portion;

receiving the additional start bit portion;

determining the start bit time based on timing of receiving the initial start bit portion and the additional start bit portion;

determining the useful bit time based on the start bit time and the integer multiple; and

receiving the useful bits at a bit rate based on the useful bit time.

22. The method according to claim 20, wherein each useful bit is transmitted at only a single level based on a logical value of that useful bit.

23. The method according to claim 20, wherein the first time period is between 60% and 90% of the start bit time.