EP1047997A1

EP1047997A1 - Method and associated device for connecting on the same serial port already in use, another peripheral

Info

Publication number: EP1047997A1
Application number: EP98964548A
Authority: EP
Inventors: Philippe Cabinet Hautier GUENEBAUD; Micka[l Cabinet Hautier LEFEVRE
Original assignee: SCM Schneider Microsysteme Microsystemes Schneider Entwick u Vert
Current assignee: SCM Schneider Microsysteme Microsystemes Schneider Entwick u Vert
Priority date: 1998-01-14
Filing date: 1998-12-30
Publication date: 2000-11-02
Also published as: FR2773626A1; JP2002509314A; WO1999036857A1

Abstract

The invention concerns a method and its associated device for connecting on the same computer serial port (6) already being used by a peripheral (A), another peripheral (B) comprising: at the computer level: a new driver (4), another software interface serving as main driver connected to the driver (3) of peripheral (A) (already being used on the serial port) and serving as slave driver and to the physical interface (UART1) serving as communication management means; at the other peripheral (B) new interface: a controlled switch (10), an interface (UART) (7) serving as communication means said two elements being mutually connected and also connected to the physical interface (UART) (5) of the computer (6) to the peripheral (A) already in use. The invention is applicable to computers.

Description

METHOD AND DEVICE FOR CONNECTING TO THE SAME SERIAL PORT ALREADY USED ANOTHER PERIPHERAL DEVICE

The subject of the invention is a method and its device for connecting to the same serial port of a computer already used by a peripheral, another peripheral.

The goal is to connect a device such as a smart card reader or any other device between a computer and a serial port already used and connected by any other device (for example a mouse, a joystick, a modem, .. .). This serial port uses a RS232 or I2C or SPI or other type of communication protocol, ...

According to the state of the art, if we take the example of the mouse, it is connected directly by a serial link. To carry out the data exchange between the mouse and the computer, a "mouse driver" and a "UART" residing in the computer (universal asynchronous transmitter / receiver) are used, which acts as a means of communication management.

It is important to note that according to the state of the art, if the user wants to use a mouse on his computer, he is obliged to configure the input / output port. used by the mouse. As a result, the user can only use the mouse on this port, and no other device can be used on the same serial port. The invention tends to solve this problem. The state of the art can be defined by the following patent: - FR-A-2,740,885: a method for managing and executing security applications within interactive electronic equipment fitted with a peripheral device comprising the secure means and pointing means, comprises an extended communication protocol of the communication protocol specific to the pointing means of said peripheral device. This protocol allows the use of a single serial port for communication between application software and the pointing means and the secure means assembled in the peripheral device according to the invention. The peripheral device integrates the pointing and terminal functions for microcircuit cards. Specifically to this invention, it includes secure storage, management and execution means for security applications. The method and apparatus according to the invention are intended for software protection applications and software license management applications, in particular on interactive electronic equipment.

The method according to the invention for connecting to the same serial port of a computer already used by a peripheral (A), another peripheral (B), consists in:

- deactivate the application driver (A), in order to then be able to transfer data without problems for the cursor controlled by the application (A),

- create a new driver to manage the application driver (A) and the serial port of the computer, - directly connect the transmission path to the universal asynchronous transmitter / receiver (UART) of the application ( B) and to the application (A), said channel is used only by the pilot of the application (A) to detect the equipment at startup, said channel is also available at all times for application (B)

- that the UART of the smart card reader cuts the application (A) as soon as it receives data and immediately sends a response to the computer,

- if the computer has not asked for data, the UART of the card reader checks that the data request has been received and informs the computer, then the computer applies an interrogation scenario, during this scenario the computer is master and the application (B) is the slave. The interrogation scenario is used in order not to disturb the user of the mouse during the response time of the card reader.

To this end, said scenario is characterized by three parts: => sending a request for main data to the card reader, then in some cases the card reader can send information to confirm that the request has been received, or the requested data directly,

=> use of interrogations to know if the smart card reader has received data from the card and if it is ready to send the main data request,

= search for the main request response data.

According to another embodiment, an additional contact supplies the “request to send” (RTS) and “ready to receive” (DSR) signals from a computer with a serial port, said contact directly links the mouse to the computer if the power supply to the smart card reader (or other device) is interrupted.

The invention also relates to the device for implementing the method. The device for connecting to the same serial port of a computer already used by a peripheral (A), another peripheral (B), is characterized in that it comprises:

* at the computer level:

- a new "driver", "other software interface" which acts as "main driver" connected on the one hand to the driver of peripheral A (already used on said serial port) and which acts as "slave driver" and on the other hand to the physical interface (UART,) which acts as a means of communication management

* at the new interface of the other device (B):

- a controlled switch - an interface (UART ₂ ) acting as a means of communication, these two elements being connected to each other and also being connected to the physical interface (UART,) of the computer to the peripheral (A) already used.

According to one embodiment, the device (A) already used on the serial port of the computer is a mouse and the other device (B) is at least a smart card reader.

The attached drawings are given as indicative and non-limiting examples. They represent an embodiment according to the invention. They will allow the invention to be easily understood.

Figure 1 is a view showing the current architecture. Figure 2 is a schematic and simplified view of the device according to the invention.

Figure 3 is a view according to Figure 2, according to another mode of presentation.

Figure 4 is a view of the scenario according to the method. During this scenario, the user can work normally with the mouse without problem.

DESCRIPTION AND ARCHITECTURE To transmit data from the computer 6 to the smart card reader 8 via the same serial port as the mouse 9, the mouse driver 3 must be deactivated, so that data can be transferred without problems for the cursor controlled by the mouse.

It is necessary to create a new driver to manage the mouse driver 3 and the serial port of the computer.

The transmission channel is connected directly to the universal asynchronous transmitter / receiver (UART) of the smart card reader 7 and to the mouse 9, this channel is used only by the mouse driver to detect the mouse hardware at system startup. It is also available at any time for the smart card application.

When it receives data, the card reader UART shuts down the mouse and immediately sends a response to the computer. Thus, the mouse user is not bothered by this discreet transmission of data.

If the computer 6 has not asked for data, the UART of the card reader 7 checks that the data request has been received and informs the computer 6, then the computer 6 applies a interrogation scenario until the smart card reader 8 receives a data request. This interrogation scenario is described further in the description and is represented in FIG. 4.

Throughout this process, the computer 6 is the master and the UART of the card reader 7 is the slave.

Figure 3 shows the architecture used:

1 / CARD READER application

2 / Operating system

3 / MOUSE pilot

4 / CARD READER driver (Driver other interface - software interface)

5 / Universal asynchronous transmitter / receiver UART 8250 - SERIAL PORT 6 / COMPUTER

CARD READER UART Interface

8 / MATERIAL OF THE CARD READER

9 / MOUSE

10 / Switch controlled

The interrogation scenario is as follows

The response time of the smart card reader 8 can be several minutes and the mouse 9 cannot remain out of service throughout this period. It is therefore necessary to use a scenario in order not to disturb the user of the mouse 9 during the response time of the card reader 8.

The scenario is divided into three phases: - In the first phase, sending a main data request to the smart card reader 8, then the card reader 8 sends information to confirm that the request has been received.

-i In the second phase, implementation of the interrogation method according to the scenario described to know if the smart card reader 8 has received data from the card (not shown) and if it is ready to send the main data request. - In the last phase, search for the response data to the main request.

The scenario is illustrated in Figure 4:

1 / Main data request

2 / Answer OK

3 / Phase 1 4 / Data request OK

5 / KO response

6 / Phase 2

Request data

8 / Phase 3 9 / Main data response

-> During this scenario, the user can work normally with the mouse 9 without problem.

It should be noted that the mouse 9 operates in the absence of power from the smart card reader 8.

Another embodiment includes another contact powered by "request to send" (RTS) and "ready to receive" (DSR) signals from a serial port computer. This contact connects the mouse directly to the computer in the event of a power failure.

The serial mouse uses a fixed-format data packet at a speed of 1200 baud to the host when a button is pressed or when mouse movement is detected.

- Reset initialization

The mouse transmits an "M" character as soon as the power is turned on or when a reset is initiated by the host. This character informs the host of the conformity of the message with the serial manufacturer format.

- Serial data message format

When transmitting data to the host, the mouse broadcasts the following data format, which conforms to the manufacturer's serial interface. The 1200 baud data format uses a 9-bit data block consisting of 7 bits of message data and 2 control bits.

The mouse controller transmits the next 3-byte data packet, conforming to the interface, in response to a mouse event. / Byte 1 of message data it Description Start bit (always 0) Bit 6 of horizontal movement Bit 7 of horizontal movement (most significant bit) Bit 6 of vertical movement Bit 7 of vertical movement (most significant bit) 1 = Button secondary pressed 1 = primary button pressed Always = 1 (message synchronization bit) Stop bit (always 1)

/ Byte 2 of message data it Designation 1 Start bit (always 0) Bit 0 of horizontal movement Bit 1 of horizontal movement Bit 2 of horizontal movement Bit 3 of horizontal movement Bit 4 of horizontal movement Bit 5 of horizontal movement

8 Always = 0

9 Stop bit (always 1)

3 / Byte 3 of message data Bit Designation

1 Start bit (always 0)

2 Bit 0 of vertical movement

3 Bit 1 of vertical movement 4 Bit 2 of vertical movement

5 Bit 3 of vertical movement

6 Bit 4 of vertical movement

7 Bit 5 of vertical movement

8 Always = 0 9 Stop bit (always 1)

UART 8250

This UART (universal asynchronous transmitter / receiver) is used to manage the serial port interface.

The UART 16550 is compatible, in software and pinout, with the 8250 but has an internal queue operating on the principle of "first in, first out" (FIFO) and can be activated and deactivated by the software.

The COMl port normally uses the address 03F8H, COM2 the address 02F8H, COM3 the address 03E8H and COM4 the address 02E8H. This lowest address is generally called the base port address and each addressable register is then referenced by relative addressing from this base value, as shown in this table: If the DLAB bit of the LCR (communication command register) = 0:

00H DATA When read, register of data received. In case of writing, transmission maintenance register (read / write). 01H 1ST Interruption validation register (read / write).

If the DLAB bit of LCR = 1:

00H BaudO BRG divider scale, low byte (read / write)

01H Baudl BRG divider scale, high byte (read / write)

Unaffected by DLAB bit:

02H IID Interrupt identifier (read) register and command register

FIFO (writing)

03H LCR Communication command register (read / write)

04H MCR Modem command register (read / write)

05H LSR Communication status register (read)

06H MSR Modem status register (read)

Port 3F8 / 3F9 - Transmission speed divider table (read / write ^ DLAB bit in LCR = 1

BITS / SECOND DIVIDER BITS / SECOND DI

50 2304 1800 64

75 1536 2000 58

110 1047 2400 48

134 857 4800 24

150 768 9600 12

300 384 19 200 6

600 192 38 400 3

1200 96 57 600 2

1800 64 115 200 1

2000 58

Divider = 1843200 / (baud rate * 16).

Port 3F8 - Interrupt validation register 1ER (read / write. ”DLAB bit in LÇR = Q

Register of data received when read. Transmission maintenance register in case of writing.

Port 3F9 - Interrupt validation register - 1st (read / write.> DLAB bit in

LCR = 0

Bit Binary Name Meaning

7,6,5,4 Reserved 0000 xxxx Reserved (zero)

3 EMI xxxx lxxx Validation of modem status interruption 2 2 E ELLII xxxx xl xx Validation of communication status interruption

1 ETI xxxx xx lx Validation of transmission register interruption

0 ERI xxxx xxx 1 Interval validation of data received ready

Port 3FA - Interruption identification register - TIR (read only) Bit Binary Name Meaning 7.6 FIQ llxx xxxx 16550 only, FIFO queues are validated.

OOxx xxxx 8250 and 16550, the FIFO queues are disabled.

5.4 Reserved xxOO xxxx Reserved (zero)

3 TINT xxxx xlxx 16550 only, int. session exit. Waiting. xxxx xOxx 8250 and 16550

1.2 SINT xxxx xOOx Modem status interrupt, bit changed in MSR xxxx xOlx Transmission register interrupt, xxxx holding register xlOx empty transmission, bit at 1 in LSR xxxx xllx Data received ready interrupt, data register pi ein, bit at 1 in LSR. Communication state interruption,

BREAK or error bit in LSR.

0 IP xxxx xxx 1 Interruption pending (no active interruption) xxxx xxxO No interruption pending

Port 3FA - 16550 FIFO command register - FCR (write only)

Bit Binary Name Meaning

7.6 TL OOxx xxxx Trigger level = 1 byte for interrupt

FIFO receiver

01 xx xxxx Trigger level = 4 bytes for interrupt

FIFO receiver lxx xxxx Trigger level = 8 bytes for interrupt

FIFO receiver llxx xxxx Trigger level = 14 bytes for interrupt

Receiver FIFO 5.4 Reserved xxOO xxxx Reserved (zero)

3 Reserved xxxx Ixxx Modification of the RXRDT & TXRDY pins from mode 0 to mode 1 2 CLT xxxx xlxx Emitter FIFO emitter

1 CLR xxxx xx lx Receiver FIFO drain

0 IP xxxx xxxl Validation emptying of sender and receiver FIFO queues

Port 3FB - Communication command register - LCR (read / write)

Bit Binary Name Meaning 7 DLAB Oxxx xxxx Relative address 0 refers to DATA, relative address 1 to 1ER command Ixxx xxxx Relative address 0 and 1 refers to the divider toggle BR address SETBRK xOxx xxxx Normal UART operation command xlxx xxxx Sends interrupt interrupt signal

5.4.3 G GEENNPPAARR xxxxxxxx OOxxxxxx No control parity bit xxOO Ixxx Parity bit = parity odd xxOl Ixxx Parity bit = pair xxlO Ixxx Parity bit = 1 xxl l Ixxx Parity bit = 0

XSTOP xxxx xOxx 1 stop bit stop bit xxxx xlxx 2 stop bits (1.5 if WL = 5) 1.0 W WDD55 xxxxxxxx xxxxOOOO Word length = 5

WD6 xxxx xxOl Word length = 6

WD7 xxxx xx 10 Word length = 7

WD8 xxxx xx 11 Word length = 8

Port 3FC - MCR modem command register (read / write)

Bit Binary Name Meaning

7.6.5 Reserved OOOx xxxx Reserved (zero)

4 TEST xxx 1 xxxx Activation of the UART self-test configuration

3 OUT2 xxxx Ixxx Control of interrupt signals 8250 (output

User2)

2 OUT1 xxxx xlxx Resetting the internal modem 1200 b Hayes (output

Userl)

1 RTS xxxx xxlx Goes to 1 the RTS output to the RS232C connector

0 DTR xxxx xxxl Goes to 1 the DTR output to the RS232C connector

Port 3FD - Communication status register - LSR (read only

Bit Binary Name Meaning

7 PE / FE / interr Ixxx xxxx PE / FE 16550 interrupt in FIFO queue

Oxxx xxxx Use of 8250 or 16450

6 TSRE xlxx xxxx Empty transmission shift register

5 THRE xxlx xxxx Empty transmission maintenance register 4 BI xxxl xxxx Interruption received 3 FE xxxx Ixxx Frame error 2 PE xxxx xlxx Parity error 1 OE xxxx xxlx Overflow error 0 DR xxxx xxxl Data received ready

Port 3FE - Modem status register - MSR (read only)

Bit Binary Name Meaning

7 DCD Ixxx xxxx Detected data carrier level

6 RI xlxx xxxx Level of call indicator

5 DSR xxlx xxxx "Ready to receive" level

4 CTS xxxl xxxx "Ready to transmit" level DCDC xxxx Ixxx Change of DCD RIC xxxx xlxx Change of RI DSRC xxxx xxlx Change of DSR CTSC xxxx xxxl Change of CTS

REFERENCES

1. CARD READER application

2. Operating system 3. MOUSE driver

4. CARD READER driver (Driver other interface - software interface)

5. Universal asynchronous transmitter / receiver UART 8250 - SERIAL PORT

6. COMPUTER

7. CARD READER UART interface 8. CARD READER HARDWARE

9. MOUSE

10. Switch controlled

Claims

1. Method, for connecting to the same serial port of a computer (6) already used by a peripheral (A), another peripheral (B), characterized in that it consists in:

- create a new driver to manage the application driver (A) and the computer serial port (6), - directly connect the transmission channel to the universal asynchronous transmitter / receiver UART (5) of the application (B) and to the application (A), said channel is used only by the pilot of the application (A) to detect the equipment at startup, said channel is also available at all times for the application ( B),

- that the UART of the card reader (7) cuts the application (A) as soon as it receives data and immediately sends a response to the computer (6),

- if the computer (6) has not asked for data, the UART of the card reader (7) checks that the data request has been received and informs the computer (6), then the computer applies an interrogation scenario, during this scenario the computer (6) is master and the application (B) is the slave.

2. Method according to claim 1, characterized in that the said scenario is characterized by three parts:

= sending a main data request to the card reader (1), then the card reader (1) sends information to confirm that the request has been received, => use of queries to find out whether the card reader smart (1) has received data from the card and is ready to send the main data request,

=> search for response data to the main request.

3. Method according to claim 1, characterized in that an additional contact supplied by the “request to send” (RTS) and “ready to receive” (DSR) signals coming from a port computer serial, directly connects the mouse (9) to the computer (6) in the event of a power failure for the smart card reader (1) (or other device).

4. Device for implementing the method according to claim 1, for connecting to the same serial port of a computer already used by a device (A), another device (B), characterized in that it includes * at the computer level: a new "driver", another software interface which acts as "main driver (4)" linked on the one hand to the device driver (A) (already used on said serial port) and which acts as "slave driver (3)" and on the other hand to the physical interface (UART,) (7) which acts as a communication management means * at the new interface of the other peripheral (B): 0 a controlled switch (10) 0 an interface ( UART ₂ ) (7) acting as a means of communication, these two elements being interconnected and also being connected to the physical interface (UART,) (5) of the computer (6) to the peripheral (A) already used.

5. Device according to claim 1, characterized in that the peripheral (A) already used on the serial port of the computer (6) is a mouse (9).

6. Device according to claim 1, characterized in that the other device (B) is a smart card reader (1).