FR2773626A1 - Adaptor for connection of peripheral to serial computer port already in use - Google Patents

Abstract

The adaptor has two parts: software for the computer and a physical adaptor. The software provides a new driver (4) which behaves as a master driver for the existing serial device (A) and also as a communication driver. The physical interface has a standard serial chip (UART) providing switched (10) communication between the computer, the existing serial device and the added peripheral.

Description

 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 12C 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 in interactive electronic equipment provided with a peripheral device comprising the secure means and pointing means, comprises an extended communication protocol of the specific communication protocol 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 of:
- 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 computer's serial port,
- to directly connect the transmission channel to the universal asynchronous transmitter / receiver (UART) of the application (B) and to the application (A), said channel is used
only by the application driver (A) to detect the hardware at startup, said
channel is also available at any time 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 did not ask 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
return of a main data request to the card reader, then in
some cases the card reader may send information to confirm the correct
receipt of the request, or directly the requested data,
=> 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 response data to the main request.

According to another production method, an additional contact supplies by the
request to send (RTS) and ready to receive (DSR) signals from
a computer with a serial port, said contact connects the mouse directly to the computer in the event of
power off the smart card reader (or other device).

 The invention also relates to the device for implementing the method.

The device to connect 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, another software interface which acts as
main driver linked on the one hand to the driver of device A (already used
on said serial port) and which acts as a slave driver and on the other hand
the physical interface (UART) which acts as a means of management
communication * at the new interface of the other device (B)
- a controlled switch
- an interface (UART2) serving as a means of communication between these two
elements being interconnected and also being connected to the physical interface
(UART,) from the computer to the device (A) already in use.

 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. operation, 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
7 / UART interface of the CARD READER
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.

 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 request for main data.

 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 / OK response 3 / Phase 1 4 / OK data request 5 / KO response 6 / Phase 2 7 / Data request 8 / Phase 3 9 / Response from main data o 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. o Initialization of Reset
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. e 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.

1 / Byte 1 of message data
Bit Designation Start bit (always O) 2 Bit 6 of horizontal movement 3 Bit 7 of horizontal movement (most significant bit) 4 Bit 6 of vertical movement 5 Bit 7 of vertical movement (most significant bit) 6 l = Secondary button pressed 7 l = Primary button pressed 8 Always = l (message synchronization bit) 9 Stop bit (always 1) 2 / Byte 2 of message data
Bit Designation Start bit (always O) 2 Bit horizontal movement 3 Bit 1 horizontal movement 4 Bit 2 horizontal movement 5 Bit 3 horizontal movement 6 Bit 4 horizontal movement 7 Bit 5 horizontal movement 8 Always = 0 9 Stop bit (always 1) 3 / Byte 3 of message data
Bit Designation
Start bit (always O) 2 Bit vertical movement O 3 Bit 1 vertical movement 4 Bit 2 vertical movement 5 Bit 3 vertical movement 6 Bit 4 vertical movement 7 Bit 5 vertical movement 8 Always = 0 9 Bit d '' stop (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 COM1 port normally uses the 03F8H address, COM2 the 02F8H address, COM3 the 03E8H address and COM4 the 02E8H address. 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
OOH DATA When read, register of data received. In case of writing, register of
transmission maintenance (read / write).

01H IER Interruption validation register (read / write).

If the DLAB bit of LCR = 1:
OOH BaudO BRG divider scale, low byte (read / write) 01H Baud i BRG divider scale, high byte (read / write)
Unaffected by DLAB bit 02H IID Interrupt identifier register (read) and FIFO command register (write) 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 DIVIDER 50 2,304 1,800 64 75 1,536 2,000 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 i 2000 58
Divider = 1843200 / (baud rate * 16).

Port 3F8 - IER interrupt validation register (read / write) DLAB bit in LCR = 0
Register of data received when read.

Transmission maintenance register in case of writing.

Port 3F9 - Interrupt validation register - IER (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 ELI xxxx xlxx Validation of communication status interruption i ETI xxxx xxlx Validation d transmission register interruption
O ERI xxxx xxxl Validation of interruption of data received ready
Port 3FA - Interrupt identification register - IIR (read only)
Bit Binary Name Meaning 7.6 FIQ 11xx xxxx 16550 only, FIFO queues are validated.

 00xx xxxx 8250 and 16550, the FIFO queues are disabled.

5.4 Reserved xx00 xxxx Reserved (zero) 3 TINT xxxx xlxx 16550 only, int. session exit. Waiting.
xxxx x0xx 8250 and 16550 1.2 SINT xxxx x00x Modem status interrupt, bit changed in MSR
xxxx x01x Interruption of transmission register, maintenance register
xxxx xiOx transmission empty, bit at 1 in LSR
xxxx xlix Interruption of data received ready, data register full, bit
to 1 in LSR. Communication state interruption,
BREAK or bit
error in LSR.

O IP xxxx xxxl Interruption pending (no active interruption)
xxxx xxx0 No interruption pending
Port 3FA - 16550 FIFO command register - FCR (write only)
Bit Binary Name Meaning 7.6 TL 00xx xxxx Trigger level = 1 byte for receiver FIFO interrupt
Olxx xxxx Trigger level = 4 bytes for receiver FIFO interrupt
10xx xxxx Trigger level = 8 bytes for receiver FIFO interrupt
i lxx xxxx Trigger level = 14 bytes for interrupt
Receiver FIFO 5.4 Reserved xx00 xxxx Reserved (zero) 3 Reserved xxxx lxxx Modification of the RXRDT & TXRDY pins from mode 0 to mode 1 2 CLT xxxx xlxx Draining FIFO transmitter
i CLR xxxx xxlx Receiver FIFO drain
O 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 IER
command lxxx xxxx Relative address 0 and 1 refers to the divider flip-flop BR
address 6 SETBRK x0xx xxxx Normal UART operation
command xlxx xxxx Sends interrupt interrupt signal.

5.4.3 GENPAR xxxx Oxxx No parity bit
check xx00 lxxx Parity bit = odd
parity xxOl lxxx Parity bit = pair
xx10 lxxx Parity bit = 1
xxii lxxx Parity bit = 0 2 XSTOP xxxx x0xx 1 single stop bit
stop bit xxxx xlxx 2 stop bits (1.5 if WL = 5) 1.0 WD5 xxxx xx00 Word length = 5
WD6 xxxx xxOl Word length = 6
WD7 xxxx xxi O Word length = 7
WD8 xxxx xxii Word length = 8
Port 3FC - MCR modem command register (read / write)
Bit Binary Name Meaning 7.6.5 Reserved 000x xxxx Reserved (zero) 4 TEST xxxl xxxx Activation of the UART self-test configuration 3 OUT2 xxxx lxxx Control of interrupt signals 8250 (User2 output) 2 OUT1 xxxx xlxx Reset 1200 b internal Hayes modem (User output)
t RTS xxxx xxlx Switches the RTS output to the RS232C connector to 1
O DTR xxxx xxxl Goes to I the DTR output to the RS232C connector
Port 3FD - Communication status register - LSR (read only)
Bit Binary Name Meaning 7 PE / FE / interr lxxx xxxx PE / FE interrupt 16550 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 Interrupt received 3 FE xxxx lxxx Frame error 2 PE xxxx xlxx Parity error 1 OE xxxx xxlx Overflow error
O DR xxxx xxx1 Data received ready
Port 3FE - Modem status register - MSR (read only)
Bit Binary Name Meaning 7 DCD lxxx xxxx Detected data carrier level 6 RI xlxx xxxx Call indicator level 5 DSR xxlx xxxx "ready to receive" level 4 CTS xxx1 xxxx "ready to transmit" level 3 DCDC xxxx lxxx Change of DCD 2 RIC xxxx xlxx Change of RI i DSRC xxxx xxlx Change of DSR
O CTSC xxxx xxx1 Change of CTS
REFERENCES
1. CARD READER application 2. Operating system
3. MOUSE driver 4. CARD READER driver (Other interface driver - software interface) 5. Universal asynchronous transmitter / receiver UART 8250 - SERIAL PORT 6. COMPUTER 7. UART interface of CARD READER 8. CARD READER HARDWARE 9. MOUSE 10. Switch controlled

Claims (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.  - 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),  - directly connect the transmission channel to the universal asynchronous transmitter / receiver the 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 any time for the application (B),  - create a new driver to manage the application driver (A) and the computer serial port (6),  - deactivate the application driver (A), in order to then be able to transfer data without problems for the cursor controlled by the application (A),  that it consists of  I. Method, for connecting to the same serial port of a computer (6) already used by a peripheral (A), another peripheral (B), characterized by the fact  2. Method according to claim 1, characterized in that  that the said scenario is characterized by three parts  return of 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 smart card reader (1) has received data from the card and whether it 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 from a computer with a serial port,  connects the mouse (9) directly 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 peripheral (A), another peripheral (B), characterized by the fact  it includes * at the computer level:  a new driver, another software interface that acts as a driver  main (4) connected on the one hand to the device driver (A) (already used  on said serial port) and which acts as slave driver (3) and other  part to the physical interface (UART1) (7) which acts as a management means  communication * at the new interface of the other device (B)  0 a controlled switch (10)  0 an interface (UART2) (7) serving as a means of communication  two elements being interconnected and also being connected to the interface  physical (UART1) (5) from the computer (6) to the device (A) already in use.  5. Device according to claim 1, characterized in that  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  that the other device (B) is a smart card reader (1).