High speed serial interface
View Patent ↗A high speed, serial interface employs a simplified protocol which minimizes overhead enabling uncompressed image data to be sent serially over a long distance in real-time devices, such as a color printer. Because the error rate experienced in high speed serial and fiber optic links is very small and finite, the protocol removes the requirement to retransmit real time data. The protocol for initiator device-target device communications includes an idle message frame for indicating a device is ready for communication; a control word frame for sending a data request from the target device; a control word frame for indicating a transfer mode from the initiator device; and a data frame, wherein in response to a data request from the target device, the initiator device transmits a control word frame followed by the requested data.
1. A high speed serial interface, comprising:
an initiator device for generating data and messages, wherein the initiator device includes a transceiver for sending and receiving data and messages using a serial protocol;
a target device for receiving data and messages, wherein the target device includes a transceiver for sending and receiving data and messages using the serial protocol; and
a transmission media for coupling the initiator device and the target device;
wherein the serial protocol comprises a plurality of time frames comprising an idle message time frame for indicating a device is ready for communication, wherein each of the initiator device and the target device transmits an idle frame when it is ready for communication; a target control word frame for sending a data request from the target device; an initiator control word frame for indicating a transfer mode from the initiator device; and a data frame, wherein in response to a target control word frame containing a data request from the target device, the initiator device transmits an initiator control word frame followed by the requested data;
wherein the initiator device comprises a digital front end (DFE), the target device comprises a printer and the transmission media comprises fiber optics; and
wherein the printer control word frame further comprises a verification bit, a mode bit, a page request bit, a line request bit, a buffer status bit and a reset status bit.
2. The high speed serial interface of claim 1 , wherein the DFE control word frame further comprises a verification bit, separation bits, a reset bit and a mode bit.
3. The high speed serial interface of claim 1 , wherein an idle frame is sent by the printer while a serial link between the printer and the DFE is operational if neither a valid control word frame nor data is requested from the DFE.
4. The high speed serial interface of claim 1 , wherein the serial protocol further comprises a reset sequence for changing mode comprising an idle frame, a DFE control word frame and an idle frame from the DFE.
5. A protocol structure for high-speed, serial digital front end (DFE)-printer communications, comprising:
a plurality of time frames comprising an idle message time frame for indicating a device is ready for communication, wherein each of the DFE and the printer transmits an idle frame when it is ready for communication;
a printer control word frame for sending a page request and a line request from the printer;
a DFE control word frame for indicating a transfer mode from the DFE; and
a data frame, wherein in response to a page request from the printer, the DFE transmits a control word frame followed by the requested data;
wherein the printer control word frame further comprises a verification bit, a mode bit, a page request bit, a line request bit, a buffer status bit and a reset status bit.
6. The protocol structure of claim 5 , wherein the DFE control word frame comprises a verification bit, separation bits, a reset bit and a mode bit.
7. The protocol structure of claim 6 , wherein the mode bit indicates a normal mode of operation and a diagnostic mode of operation.
8. The protocol structure of claim 7 , wherein normal mode means transmission of data from the DFE to the printer.
9. The protocol structure of claim 5 , wherein an idle frame is sent by the printer while a serial link between the printer and the DFE is operational if neither a valid control word frame nor data is requested from the DFE.
10. The protocol structure of claim 5 , further comprising a reset sequence for changing mode comprising an idle frame, a DFE control word frame and an idle frame from the DFE.
11. A method of transmitting data between an initiator device and a target device using a high speed, serial interface, comprising:
transmitting, from the initiator device, an idle message frame indicating the initiator device is ready for transmission;
transmitting, from the target device, an idle message frame indicating the target device is ready for communication;
transmitting, from the target device, a target control word frame requesting transmission of data from the initiator device;
transmitting, from the initiator device in response to a target control word frame containing the data request from the target device, an initiator control word frame indicating a data transfer mode and the requested data;
wherein the initiator device comprises a digital front end (DFE) and the target device comprises a printer; and
wherein the printer control word frame further comprises a verification bit, a mode bit, a page request bit, a line request bit, a buffer status bit and a reset status bit.
12. The method of claim 11 wherein the DFE control word frame further comprises a verification bit, separation bits, a reset bit and a mode bit.
13. The method of claim 11 , wherein an idle frame is sent by the printer while the serial link is operational if neither a valid control word frame nor data is requested from the DFE.