Multiplex interface for a communication controller
First Claim
1. A multiplex interface (17,3) for interconnecting a line scanning means (1) of a communication controller, in order to exchange data and control bits, to user lines attached to the communication controller, characterized in that said multiplex interface comprises:
- transmit and receive synchronous multiplex links (3-T,3-F) connecting the line scanning means to the users through multiplexing means (17), the data and control bits being exchanged on the transmit and receive multiplex links in synchronous frames wherein at least two slots are assigned to each user, the structure of the two slots being identical for all types of users and comprising;
an n-bit data slot which includes a variable number x of valid bits depending upon the speed of the user information carrying medium (line or multiplex link) assigned to the data slot, said number being indicated by a variable delimitation pattern comprising a first delimiting bit set at a first binary value (1) adjacent to the data bits and (n-x-1) bits set at the second binary value (0) adjacent to said first delimiting bit; and
an n-bit control slot wherein a first bit is used as global validation bits in case the data slot comprises n valid bits (x=n), this bit being set at the first binary value (1) when the data slot comprises n valid bits and at the second binary value (0) if it comprises less than n valid bits, and the n-1 other bits being used for exchanging control information;
said multiplexing means including;
frame synchronization detecting means (30,
32) responsive to the bit stream on at least one multiplex link (3-T or 3-R) for generating therefrom a frame synchronization signal delimiting the succession of slots in the successive frames and a bit clock signal at the bit rate on the multiplex link;
slot time allocating means (54,
50) responsive to the bit clock signal and to the frame synchronization signal for generating selection signals (66) which are active to indicate the two slot periods assigned to the users;
at least one receiving means, each one of the receiving means (FIG.
8) receiving the data and control bits from one attached user at the speed of the user information carrying medium and arranging them into entities having the structure of the data and control bit slots to be sent on the receive link (3-R), said entities being sent to the line scanning means when the selection signal relative to the user is active;
at least one transmitting means (FIG.
10), each one of the transmitting means receiving the bits from the transmit link arranged in data and control slots and responsive to the selection signal relative to the user for causing the valid data bits and the control bits to be sent to the user at the user information carrying medium speed.
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Accused Products
Abstract
A multiplex interface for interconnecting the line scanning means (1) of a communication controller to user lines via transmit and receive synchronous multiplex links. Both data and control bits are exchanged in synchronous frames wherein at least two slots are assigned to each user line, the structure of the two slots is identical for all types of user lines and includes an n-bit data slot having a variable number x of valid bits depending upon the line speed of the user line assigned to the data slot and indicated by a variable delimiter pattern comprising a first delimiting bit set at a first binary value (1) adjacent to the data bits and (n-x-1) bits set at the second binary value (0) adjacent to said first delimiting bit, and an n-bit control slot having a first bit used as a global validation bit in case the data slot comprises n valid bits (x=n), this bit being set at the first binary value (1) when the data slot comprises n valid bits and at the second binary value (0) if it comprises less than n valid bits, and the n-1 following bits are used for exchanging control information.
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Citations
10 Claims
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1. A multiplex interface (17,3) for interconnecting a line scanning means (1) of a communication controller, in order to exchange data and control bits, to user lines attached to the communication controller, characterized in that said multiplex interface comprises:
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transmit and receive synchronous multiplex links (3-T,3-F) connecting the line scanning means to the users through multiplexing means (17), the data and control bits being exchanged on the transmit and receive multiplex links in synchronous frames wherein at least two slots are assigned to each user, the structure of the two slots being identical for all types of users and comprising; an n-bit data slot which includes a variable number x of valid bits depending upon the speed of the user information carrying medium (line or multiplex link) assigned to the data slot, said number being indicated by a variable delimitation pattern comprising a first delimiting bit set at a first binary value (1) adjacent to the data bits and (n-x-1) bits set at the second binary value (0) adjacent to said first delimiting bit; and an n-bit control slot wherein a first bit is used as global validation bits in case the data slot comprises n valid bits (x=n), this bit being set at the first binary value (1) when the data slot comprises n valid bits and at the second binary value (0) if it comprises less than n valid bits, and the n-1 other bits being used for exchanging control information; said multiplexing means including; frame synchronization detecting means (30,
32) responsive to the bit stream on at least one multiplex link (3-T or 3-R) for generating therefrom a frame synchronization signal delimiting the succession of slots in the successive frames and a bit clock signal at the bit rate on the multiplex link;slot time allocating means (54,
50) responsive to the bit clock signal and to the frame synchronization signal for generating selection signals (66) which are active to indicate the two slot periods assigned to the users;at least one receiving means, each one of the receiving means (FIG.
8) receiving the data and control bits from one attached user at the speed of the user information carrying medium and arranging them into entities having the structure of the data and control bit slots to be sent on the receive link (3-R), said entities being sent to the line scanning means when the selection signal relative to the user is active;at least one transmitting means (FIG.
10), each one of the transmitting means receiving the bits from the transmit link arranged in data and control slots and responsive to the selection signal relative to the user for causing the valid data bits and the control bits to be sent to the user at the user information carrying medium speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification