IRDA communication IC, electronic apparatus and externally-fitted communication apparatus having such an IRDA communication IC, and method of adding an IRDA communication function

IrDA communication IC, electronic device and external communication device installed with such an IrDA communication IC and method for adding an IrDA communication function

The This invention relates to an IrDA communication IC for add a communication function, the IrDA (Infrared Data Association) standards met, to an electronic device, which is provided with a data transfer port, such as a DSC (Digital Still Camera), a personal computer, a Portable data terminal (also referred to as PDA (Personal Digital Assistant)), or a printer. The present invention relates and also to an electronic apparatus having such IrDA communication IC also to an externally. installed communication device with a such IrDA communication IC, and is designed so that it externally can be installed in such an electronic device.

In recent years is the IrDA standards fulfilling infrared communication widely used as means for communication between a terminal, such as a personal computer and an external device provided with this is connected, has been used, whereby a wireless communication between the terminal and the external device is achieved. For example, in Japanese Patent Application Laid<patcit><text>JP 09326800 A</text></patcit> a An apparatus for achieving such infrared communication which complies with the IrDA standards, and a method for controlling such a device proposed.

In of the <figref idrefs="S35">9</figref> is a block circuit diagram the internal structure of the infrared communication device, which in Japanese Patent Application Laid-Open <patcit><text>JP 09329800 A</text></patcit> disclosed is shown. The in<figref idrefs="S35">9</figref> shown Infrared communication device has a CPU (Central Processing Unit) <figref>101</figref> for controlling of the entire device, a ROM (Read Only Memory) <figref>102</figref> to the Storing a program by the CPU <figref>101</figref> is performed, a RAM (Random Access Memory) <figref>103</figref> for storing the data, by the CPU <figref>101</figref> are used, an external memory <figref>104</figref> to the Storing a file, and other data from the CPU <figref>101</figref> used be, an operating range <figref>105</figref>Through which the device is operated, a display area <figref>106</figref>, A UART (Universal usable asynchronous receiver-transmitter) <figref>107</figref> to the Replacing parallel data with a bus <figref>112</figref>, A modulation section <figref>108</figref> to the Modulating a signal from the UART <figref>107</figref> is output, a demodulating <figref>109</figref> for demodulating a Signal generated by an infrared receiver section <figref>111</figref> receive is, and for supplying of the demodulated signal to the UART <figref>107</figref>, An infrared transmitter range <figref>110</figref> to the Sending infrared rays according to an Signal output from the modulation range <figref>108</figref>, The above mentioned Infrared receiver range <figref>111</figref> and mentioned the above bus <figref>112</figref> for connecting the units <figref>101</figref> to <figref>107</figref> together.

Around an existing terminal which no IrDA communication capability has incorporated, add an IrDA communication function, the internal structure must the terminal be modified as described above, an infrared communication device to build. To achieve this, one needs an extra software program added be, which achieves the IrDA communication. Such a software program has a considerably great Scope, and therefore must in cases where an already existing terminal is modified to a to form infra-red communication device, the CPU <figref>101</figref> more quickly run to perform the software program, and there are greater storage capacity in its ROME <figref>102</figref> and RAM <figref>103</figref> required. Thus, it is unavoidable, the operating characteristics of the CPU of the existing terminal to increase and also the capacity the ROM and RAM to increase.

Disadvantageously needs this infrared communication device having a faster working CPU <figref>101</figref> and a larger capacity of the ROM <figref>102</figref> and the ROM <figref>103</figref> has, correspondingly more electrical power.

Out <patcit><text>JP 5786921 A</text></patcit> is an IrDA communication IC is known which is provided inside of an electronic device and consists of an input / output interface for converting of data into parallel data, a protocol control circuit for Converting the parallel data into an IrDA protocol compliant signal, a modulation circuit for modulating the IrDA compliant signal and a demodulation circuit for demodulating the signal from outside fed is, the protocol control also the operation of the modulation circuit and Demodulationschaltung controls.

Out <patcit><text>US 5786921 A</text></patcit> is a level conversion circuit for converting RS232 raw signals into signals with RS-level and vice versa. The signals with RS 232 level then the connection for external devices to disposal posed.

&lt;?page 3?&gt;

The Object of the present invention is to provide an IrDA communication IC create, which has a communication function that the IrDA standards fulfilled.

These Object is achieved according to the invention by the features of claim 1.

advantageous Embodiments result from the dependent claims.

The Features of the present invention will become apparent from the following description, in connection with preferred embodiments and with reference to the performed accompanying figures it will rise, in which:

<figref idrefs="S28">1</figref> on Block diagram of an example of the internal structure of an IrDA communication IC according to the invention;

<figref idrefs="S29">2A</figref> and <figref idrefs="S29">2 B</figref> Block Diagrams the relationship between the in <figref idrefs="S28">1</figref> shown IrDA communication IC and an input-output device that connected to this is;

<figref idrefs="S30">3</figref> on Block diagram of another example of the internal structure of a IrDA communication IC according to the invention;

<figref idrefs="S31">4A</figref> and <figref idrefs="S31">4B</figref> Block Diagrams the relationship between the in <figref idrefs="S30">3</figref> shown IrDA communication IC and a connection with this input-output device.

<figref idrefs="S32">5</figref> on Block diagram of the internal structure of an electronic appliance with a built therein IrDA fulfilling Communication function as the first embodiment of the invention;

<figref idrefs="S32">6</figref> on Block diagram of the internal structure of an electronic appliance with an associated externally installed communication device as a second embodiment the invention;

<figref idrefs="S33">7</figref> on Block diagram of the internal structure of an electronic appliance with an associated externally installed communication device as a third embodiment the invention;

<figref idrefs="S34">8th</figref> on Block diagram of the internal structure of an electronic appliance with an externally installed communication device associated as A fourth embodiment the invention; and

<figref idrefs="S35">9</figref> on Block diagram of the internal structure of a conventional IC device having an infrared communication function.

First example an IrDA communication IC

On Example of the internal structure of an IrDA communication IC according to the present Invention will be described below with reference to FIGS. The<figref idrefs="S28">1</figref> is is a block diagram showing the internal structure of an IrDA communication IC shows that an IrDA-fulfilling (Complying) has communication function according to the invention. The<figref idrefs="S29">2A</figref> and <figref idrefs="S29">2 B</figref> are Block circuit diagrams showing the relationship between the main CPU, the terminal, which is connected to the IrDA communication IC, and the IrDA communication IC itself controls.

The in the <figref idrefs="S28">1</figref> IrDA communication IC shown has a CPU <figref>2</figref> to the Controlling the entire IrDA communication IC <figref>1</figref>, A ROM <figref>3</figref> to the Storing a software program for achieving IrDA-fulfilling Communication, a RAM <figref>4</figref> for storing the data and temporarily storing the instruction codes during IrDA communication fulfilling, a timing circuit <figref>5</figref> to prohibit the reception operation for a predetermined period of time after the transmission operation, a timing circuit <figref>6</figref> to check whether from an external electronic device, a signal comes or not by periodically activating a predetermined portion of the IrDA communication IC <figref>1</figref> to the Exchange of commands, a PIO (parallel input-output control)<figref>7</figref> to the Obtaining the compound with an interface, such as in a Od printer. Like. Is provided which the Centronics standards met, a UART (universal asynchronous receiver-transmitter usable) <figref>8th</figref> to the Obtaining the compound with an interface, such as in a portable terminal od. like. vorgsehen is that od the RS-232C standards. like. met, modulation circuit <figref>9</figref> for modulating data, a demodulation circuit <figref>10</figref> to the Demodulating a received signal, a PIO <figref>11</figref> to the Receiving data for setting the IrDA communication IC <figref>1</figref> to the Outputting the current settings of the IrDA communication IC <figref>1</figref>. a control register <figref>12</figref> for supplying the modulation circuit <figref>9</figref> and the demodulation circuit <figref>10</figref> with instructions to refer to the communication rate, the transmission pulse width and the like., an interrupt <figref>13</figref> to send an interrupt request to the CPU <figref>2</figref>. and a bus <figref>14</figref> to achieve an exchange of data between the assemblies <figref>2</figref> to <figref>12</figref>,

If an IrDA communication IC <figref>1</figref> with the above-described Building to an existing terminal, such as a PC or a portable telephone is connected, with a equipped interface is the &lt;?page 4?&gt;RS-232 standards od. Like. Satisfied, as in the <figref idrefs="S29">2A</figref> shown, exchanges the main CPU <figref>15a</figref>Which is provided inside the terminal is, data on the UART <figref>8th</figref> the IC <figref>1</figref> to the CPU <figref>2</figref>, the ROME <figref>3</figref>, RAM <figref>4</figref>, The time circuits <figref>5</figref> and <figref>6</figref>. the control register <figref>12</figref> and the interrupt controller <figref>13</figref>. which together form a protocol controller <figref>16</figref> form, from.

If the same IrDA communication IC <figref>1</figref> with an existing terminal is connected, such as a printer having an interface equipped is fulfilling the Centronics standards, such as IEEE 1285, as This in <figref idrefs="S29">2 B</figref> shown, exchanges Main CPU <figref>15b</figref>Which is disposed within the terminal device, via the PIO <figref>7</figref> the IrDA communication IC <figref>1</figref> with the above said protocol controller <figref>16</figref> Data from.

The protocol controller <figref>16</figref> processing data to this data to convert, which are adapted to the protocol required by the IrDA standards becomes. This IrDA protocol-compliant data is then passed through the modulation circuit <figref>9</figref> modulated, and then as an infrared signal from an IrDA transceiver <figref>17</figref> Posted. Conversely, an infrared signal from the IrDA transmitter-receiver <figref>17</figref> receive has been, by the demodulation circuit <figref>10</figref> demodulates, to be converted into data IrDA protocol compliant, the then a protocol controller <figref>16</figref> be supplied and through these are processed.

In this IrDA communication IC <figref>1</figref> with the above-described Structure sends the modulation circuit <figref>10</figref> a signal INT <figref>3a</figref> at the interrupt controller <figref>13</figref>When the IrDA transmitter-receiver <figref>17</figref>. with the IrDA communication IC <figref>1</figref> is connected to a Infrared signal receiving. As a result, the interrupt controller sends <figref>13</figref> a Interrupt request to the CPU <figref>2</figref>, The CPU <figref>2</figref> to , Instruct that they a control operation is carried out, an IrDA-fulfilling Receiving operation according to the software program, the in ROM <figref>3</figref> is stored to perform.

In this case data are converted into data standards the correspond, according to which the data between the IrDA communication IC <figref>1</figref> and the exchanged with the associated terminal be, and this converted data is then passed through the UART <figref>8th</figref> or PIO <figref>7</figref> to the main CPU <figref>15a</figref> or. <figref>15b</figref> passed. If the amount of data in the UART <figref>8th</figref> or PIO <figref>7</figref> for outputting to the CPU <figref>15a</figref> or <figref>15b</figref> is maintained smaller is than a predetermined amount, the UART sends <figref>8th</figref> or PIO <figref>7</figref> signals INT <figref>6a</figref> or INT <figref>6b</figref> to the interrupt <figref>13</figref>, As a result, the interrupt controller sends<figref>13</figref> a Interrupt request to the CPU <figref>2</figref>, The CPU <figref>2</figref> to , Instruct that they the control operation in such a manner is carried out, that the UART <figref>8th</figref> or PIO <figref>7</figref> the data outputs generated by the protocol control <figref>16</figref> converted are.

If On the other hand, the UART <figref>8th</figref> or PIO <figref>7</figref> Data from the Main CPU <figref>15a</figref> or. <figref>15b</figref> the terminal which with the IrDA communication IC <figref>1</figref> connected is receiving sends the UART <figref>8th</figref> or PIO <figref>7</figref> a signal INT <figref>5a</figref> or INT <figref>5b</figref> to the interrupt controller <figref>13</figref>, As a result, sends the interrupt controller <figref>13</figref> a request to the CPU <figref>2</figref>. to the CPU <figref>2</figref> to instruct that it comprises a control operation performs, to the IrDA-fulfilling Transmission process according to the ROM <figref>3</figref> saved perform software program. In this case, the data from UART be <figref>8th</figref> or PIO <figref>7</figref> receive have been converted data in IrDA protocol-compliant and are Then, the modulation circuit <figref>9</figref> supplied. The data obtained by the modulation circuit <figref>9</figref> have been modulated, then as an infrared signal from the IrDA transmitter-receiver <figref>17</figref> Posted.

Of the Transmitting and receiving process described above is not constant performed. in the individual working time circuit <figref>6</figref> so that when the IrDA communication IC <figref>1</figref> for a predetermined period is kept turned on, without the PIO <figref>7</figref> or UART <figref>8th</figref> any receive data and without the demodulation <figref>10</figref> any signal, the remaining part the IrDA communication IC <figref>1</figref> to the circuits of the non- for operating the timer circuit <figref>6</figref> heard and the circuits reception are net zugeord such as the demodulation circuit <figref>10</figref>, switched off are. In this manner, the state of the connection with the communication partner by repeating the transmission and Receiving process checked, and this is achieved in that the timing <figref>6</figref> a signal INT <figref>2</figref> to the interrupt controller <figref>13</figref> sends, to to the CPU <figref>2</figref> to schikken an interrupt request.

Furthermore must after a transmission process using a light emitting device (Not shown) carried out has been positioned within the IrDA transmitter-receiver <figref>17</figref> scheduled is a period of time (called an orbital period) to ensure in which the receiving operation is prohibited because the receiving process by the use of a light sensing device (not shown) accomplished is arranged near the light emitting device. To achieve this, the timer circuit operates <figref>5</figref> so that they the Receiving operation prohibited during this period. In this way Example, during a predetermined time (round trip time) a receiving operation prohibited, and this is achieved in that the time circuit <figref>5</figref> is caused a signal INT <figref>1</figref> to the interrupt controller <figref>13</figref> to email, &lt;?page 5?&gt;to to the CPU <figref>2</figref> an interrupt request to send.

Second Example of IrDA communication IC

On Another example of the internal structure of an IrDA communication IC according to the invention vorliegeden will be described below with reference to FIGS.

<figref idrefs="S30">3</figref> shows a block diagram of the internal structure of a further IrDA communication IC with an IrDA-fulfilling Communication function according to the invention. The <figref idrefs="S31">4A</figref> and <figref idrefs="S31">4B</figref> are block diagrams, the relationship between the main CPU, which is connected to the IrDA communication IC terminal and the IrDA communication IC itself controls. It should be noted that in the<figref idrefs="S30">3</figref>. <figref idrefs="S31">4A</figref> and <figref idrefs="S31">4B</figref> those Components, which are also in the <figref idrefs="S28">1</figref>. <figref idrefs="S29">2A</figref> and <figref idrefs="S29">2 B</figref> are contained, are denoted by the same reference numerals and symbols, and their not repeated detailed description in the following description becomes.

The in the <figref idrefs="S30">3</figref> IrDA communication IC shown <figref>1</figref> is with a FIFO circuit <figref>18</figref> provided that the modulation circuit <figref>9</figref> connected is to get out of data to send to accumulate (in this example 31 bytes consisting) via the bus <figref>14</figref> supplied have been, and a FIFO circuit <figref>19</figref> is connected to the demodulation circuit <figref>10</figref> connected to demodulated data to accumulate (in this example from 31 bytes composed) at the demodulation circuit <figref>10</figref> output are. Thus, exchanges of bus<figref>14</figref> Data with the modulation circuit <figref>9</figref> and the demodulation circuit <figref>10</figref> not directly, but through the FIFO circuits <figref>18</figref> and <figref>19</figref> out. demodulation<figref>9</figref>. the demodulation circuit <figref>10</figref> and the FIFO circuits <figref>18</figref> and <figref>19</figref> form together a modulation / demodulation circuit <figref>20</figref>,

In this IrDA communication IC <figref>1</figref>As shown in <figref idrefs="S31">4A</figref> and <figref idrefs="S31">4B</figref> shown, As with the above-described first example, the data the UART <figref>8th</figref> or PIO <figref>7</figref> the protocol controller <figref>16</figref> supplied to to be converted into data IrDA protocol-compliant if the UART <figref>8th</figref> or PIO <figref>7</figref> of the main CPU <figref>15a</figref> or. <figref>15b</figref> the terminal, which with the IrDA communication IC <figref>1</figref> is connected, receives. The converted data is then the modulation demodulation circuit <figref>20</figref> supplied. The so by the protocol controller <figref>16</figref> the modulation / demodulation circuit <figref>20</figref> forwarded Data are then passed through the FIFO circuit <figref>18</figref> the modulation circuit <figref>9</figref> passed, to be modulated. The modulated data is then the IrDA transmitter-receiver<figref>17</figref> supplied to to be sent to this as an infrared signal.

If the amount of accumulated data one byte or less equal, sends the FIFO circuit <figref>18</figref> a signal INT <figref>4b</figref> at the interrupt controller <figref>13</figref>, As a result, sending the interrupt <figref>13</figref> a control request to the CPU <figref>2</figref>, around the CPU <figref>2</figref> to instruct that, a control operation according to the software program in the ROM <figref>3</figref> is stored, carried, in that the the protocol controller <figref>16</figref> edited data on the PIO <figref>7</figref> or UART <figref>8th</figref> are output, and then the data of the FIFO <figref>18</figref> are supplied.

If on the other hand of the IrDA receiver <figref>17</figref> on Infrared signal, a corresponding signal to the demodulation circuit of this <figref>10</figref> passed, to be demodulated. The resulting data is demodulated so and IrDA protocol-compliant Data are converted, then the FIFO circuit <figref>19</figref> supplied. The FIFO circuit<figref>19</figref> sends a signal INT <figref>3b</figref> to the interrupt controller <figref>13</figref>. if the amount of accumulated data in it is equal to 8 bytes or more will. As a result, the interrupt controller sends<figref>13</figref> a Interrupt request to the CPU <figref>2</figref>, The CPU <figref>2</figref> to , Instruct that they the control operation is carried out so, that the Data within the FIFO circuit <figref>17</figref> the protocol controller <figref>16</figref> be supplied and the protocol controller <figref>16</figref> then a processing similar to that during the the receiving process is performed in the first example described above, performs.

in this connection wears Use of the FIFO circuits <figref>18</figref> and <figref>19</figref> to at which CPU <figref>2</figref> before controlling the entire protocol controller <figref>16</figref> and the Modulation / demodulation circuit <figref>20</figref> simultaneously perform all time points, and thereby it becomes possible to a desired perform control operation, without the Performance of the CPU <figref>2</figref> greatly increases.

In an IrDA communication IC according to the present Invention may further comprise a terminal for receiving an external its clock signal is provided, which on the IrDA communication IC works holds. In this case, the main CPU feeding stopping of the clock to the IrDA communication IC, when the electronic Device, which the IrDA communication IC has built, no infrared communication requires. stopping the entire operation of IrDA communication IC in this way and ways to conserve power, it is possible, a power saving function to realize, which contributes to to achieve a further reduction in power consumption.

A IrDA communication IC according to the present Invention may further provided with a power-saving connection be to receive from the main CPU an instruction to the &lt;?page 6?&gt;clock to stop holding the IrDA communication IC during operation. In this Case, the main CPU when the electronic apparatus in which the IrDA communication IC is installed, no infrared communication requires an instruction notification to the generation of the clock to stop holding the IrDA communication IC during operation. By the Stopping the operation of the entire IrDA communication IC in this way and ways to save power, it is possible, a power saving function to realize, which contributes to to achieve a further reduction in power consumption.

in the be referred to as embodiments of the present invention provides an electronic device that an IrDA communication IC as described above, has some externally installed and communication devices to add a IrDA meets end Communication function to an existing electronic device based the drawings.

first embodiment

A first embodiment the invention is described below with reference to a drawing.

<figref idrefs="S32">5</figref> is is a block diagram showing the internal structure of an existing electronic device with added IrDA fulfilling Communication function shows.

As in the <figref idrefs="S32">5</figref> shown, the electronic device according to this has embodiment with added IrDA fulfilling Communication function, a main CPU <figref>15</figref>That in the already existing electronic device is provided, a level conversion driver for converting the Voltage level of the data output from the main CPU <figref>15</figref> in the Voltage level which is required to allow the data on a transfer cable be that for exchanging data with an external electronic used machine is, and for converting the voltage level of data over a ladder <figref>23</figref> supplied have been, in a voltage level which is required to allow that the Data by the main CPU <figref>15</figref> are processed, a ladder <figref>23</figref>connected, to which a cable or the. like. is to allow an exchange of data, and that the standards according to RS-232 Centronics or fulfilled an IrDA communication IC <figref>1</figref> for processing IrDA protocol-compliant Data and an IrDA transmitter-receiver <figref>17</figref> to the Exchange of infrared signals. The IrDA communication IC<figref>1</figref> Has described a structure as in the above <figref idrefs="S28">1</figref> and <figref idrefs="S30">3</figref> shown is.

In this embodiment is in the already existing electronic device of Start the main CPU <figref>15</figref>, The conversion driver <figref>22</figref> and the conductor <figref>23</figref> has the data transmission path, wherein the Main CPU <figref>15</figref> and the level conversion driver <figref>22</figref> combines, bifurcated to also with the IrDA communication IC <figref>1</figref> connected to be, in turn, with the IrDA transmitter / receiver <figref>17</figref> connected is. In this way is the existing electronic device a IrDA fulfilling Communication function added.

in this connection is for In the event that the Data received from the main CPU <figref>15</figref> are processed, the RS-232C standards od. like. meet, the forked path between the main CPU <figref>15</figref> and the level conversion driver <figref>22</figref> With the UART <figref>8th</figref> (<figref idrefs="S28">1</figref> or <figref idrefs="S30">3</figref>) connected, in the IrDA communication IC <figref>1</figref> is provided. on the other hand is for In the event that the same Data meet the Centronics standards, the forked path between the main CPU <figref>15</figref> and the level conversion driver <figref>22</figref> With the PIO <figref>7</figref> (<figref idrefs="S28">1</figref> or <figref idrefs="S30">3</figref>) connected, the within the IrDA communication IC <figref>1</figref> is provided.

Second embodiment

in the Next, a second embodiment the invention with reference to drawings described. <figref idrefs="S32">6</figref> is a block diagram to as a second embodiment of the invention Internal structure of an existing electronic device shows the connected to a communication device installed externally is. It should be noted that such Components in the second embodiment for the same Purposes such as the first embodiment be used, designated by the same reference numerals and symbols are, and that the detailed description is not repeated.

at this embodiment is the data transmission path, the provided within the existing electronic device is to switch between main CPU <figref>15</figref> and level conversion driver <figref>22</figref> to combine, bifurcated to also connect to a conductor <figref>31</figref> to provide, in addition is provided to an external electronic connect Device allow. This conductor <figref>31</figref> is the communications device installed externally <figref>40a</figref> connected, comprising a conductor <figref>32</figref>, To allow a connection with the Head <figref>31</figref>, An IrDA communication IC <figref>1</figref> to Achieving IrDA-fulfilling Communication and an IrDA transmitter / receiver <figref>17</figref> To exchange infrared signals has.

If the Head <figref>32</figref>Which within this externally installed communication device <figref>40a</figref> scheduled is, with the conductor <figref>31</figref> is connected, the inside of the existing electronic device is provided, exchange the main CPU <figref>15</figref> and &lt;?page 7?&gt;the IrDA communication IC <figref>1</figref> via conductors <figref>31</figref> and <figref>32</figref> raw Data out. In other respects, the second embodiment operates in the same manner as the first embodiment and therefore no detailed given description of how the second embodiment operates. In this Embodiment, if the main CPU <figref>15P</figref> Raw data outputs, the RS-232C standards fulfill, the Head <figref>32</figref> to the UART <figref>8th</figref> (<figref idrefs="S28">1</figref> or <figref idrefs="S30">3</figref>) connected, within the IrDA communication IC <figref>1</figref> is provided; if the main CPU <figref>15</figref> Raw data outputs, the Centronics standards fulfill, is the Head <figref>32</figref> to the PIO <figref>7</figref> (<figref idrefs="S28">1</figref> or <figref idrefs="S30">3</figref>) connected, within the IrDA communication IC <figref>1</figref> is provided.

Third embodiment

A third embodiment the invention is described below with reference to a drawing. <figref idrefs="S33">7</figref> is is a block diagram showing the third embodiment of the invention as Internal structure of an existing electronic device shows, the is connected to a communication device externally installed. It should be noted is that such components, in the third embodiment for the same Purposes such as in the second embodiment be used, designated by the same reference numerals and symbols and in that the detailed description is not repeated.

at this embodiment allows the externally installed communications device that the existing electronic device without any modification to the same IrDA fulfilling communication function added becomes. The externally installed communication device<figref>40b</figref> this embodiment has a conductor <figref>41</figref>, The same standards, such as RS-232C or Centronics satisfies standards as the Head <figref>23</figref> of existing electronic device does, a level conversion driver <figref>42</figref> to the Converting the voltage level of raw data, the conductors on the <figref>41</figref> initiated are in a level which is required to allow that the raw data through the IrDA communication IC <figref>1</figref> are processed and converting the voltage level of the raw data output from the IrDA communication IC <figref>1</figref> in the level which is required to allow the raw data between the conductors <figref>23</figref> and <figref>41</figref> transfer be, an IrDA communication IC <figref>1</figref> to achieve IrDA fulfilling Communication and an IrDA receiver <figref>17</figref> To exchange of infrared signals.

If the Head <figref>41</figref>, The inside of the communication device externally installed <figref>40b</figref> scheduled is, with the conductor <figref>23</figref> is connected, the inside of the existing electronic device is provided, exchange the main CPU <figref>15</figref> and the IrDA communication IC <figref>1</figref> via conductors <figref>23</figref> and <figref>41</figref> and by the level conversion driver <figref>22</figref> and <figref>42</figref> raw Data out. In terms of other aspects of the third embodiment operates in the same Manner as the first embodiment and therefore no detaillerte description will be given, as the third embodiment works. In this embodiment, the level conversion driver <figref>42</figref> to the UART <figref>8th</figref> (<figref idrefs="S28">1</figref> or <figref idrefs="S30">3</figref>) connected, within the IrDA communication IC <figref>1</figref> is provided, if the main CPU <figref>15</figref> Data outputs, the RS-232C standards od meet like..; if the main CPU <figref>15</figref> Data outputs, the Centronics standards meet od. like., is the Pegelumwand development driver <figref>42</figref> to the PIO <figref>7</figref> (<figref idrefs="S28">1</figref> or <figref idrefs="S30">3</figref>) connected, within the IrDA communication IC <figref>1</figref> scheduled is.

In cases where there is no need, a cable or the. like. to use, the RS-232C Centronics or other standards met to the externally installed communication device <figref>40b</figref> at the electronic device to join, can the level conversion driver <figref>22</figref> and <figref>42</figref> from the electronic device and the externally installed communication device <figref>40b</figref> omitted will.

Fourth embodiment

in the following, with reference a Fig. A fourth embodiment of the invention. <figref idrefs="S34">8th</figref> is a Block diagram showing the fourth embodiment of the invention as Internal structure of an existing electronic device shows the connected to a communication device installed externally is. It should be noted, is that those Components in the fourth embodiment for the same Purposes as in the third embodiment be used, designated by the same reference numerals and symbols and in that the detailed description is not repeated.

In the externally installed communication device <figref>40c</figref> this embodiment and compared with the communication device externally installed <figref>40b</figref> of the third embodiment is the data transmission path, which between the conductor <figref>41</figref> and the level conversion driver <figref>42</figref> runs, forked, in addition to with the provided conductor <figref>43</figref> to be connected. This externally installed communication device <figref>40c</figref> serves, when the conductor <figref>23</figref> is connected, not only to the existing electronic device an IrDA communication function fulfilling add, but also as a conductor, which permits that another external device to your existing electronic device connected by a cable becomes.

in this connection is the head <figref>43</figref> a conductor diesel&lt;?page 8?&gt;ben standards as the Head <figref>41</figref> fulfilled. The fourth embodiment operates in the same manner as the third embodiment, an IrDA-fulfilling Communication to achieve, and therefore no detailed description given as the fourth embodiment works.

A IrDA communication IC according to the present Invention allows easy addition of IrDA-fulfilling Communication function to an existing electronic device without significant modifications of CPU, ROM and RAM, which in the electronic equipment provided are and the software that is stored in the ROM. Furthermore while the IrDA-met Communication, the CPU of the electronic apparatus is prevented from fulfilling the IrDA communication to work, and this contributes instrumental in the to-handle from the CPU of the electronic device to load reduce and simultaneously fulfilling IrDA power consumption during to reduce communication.

By Providing a first and second FIFO circuit for temporary Storing data, it is possible that the CPU of the protocol control during the transmitting and receiving operation, a control operation within perform their performance limits can thereby revising the CPU is prevented. Furthermore limit the first and second FIFO circuits in each case the amount of data, in those for outputting at a later Time are accumulated, and therefore suffer the first and second FIFO circuits not at an overflow the fact accumulated data.

Furthermore , an IrDA communication IC according to the present invention be designed such that the Operation of the other part of the IrDA communication IC as the circuits, which are associated with a first timing circuit stops. This helps when the power consumption during the Non-compliance performing the IrDA-met to reduce communication. Furthermore, by providing 'a second time circuit, a receiving operation for a predetermined time after the transmitting operations are prohibited, a malfunction result of the implementation a receiving operation during an orbital period can be prevented.

On electronic device according to the present invention allows it, that IrDa fulfilling Communication function simply by installing an IrDA communication IC, the IrDA fulfilling Communication function, has to be added, and thus allowed, that a IrDA fulfilling Communication function is added to this without the hardware and the software of the electronic device must be modified in size. Furthermore by providing an existing electronic device, which no IrDA fulfilling Communication function has, with an additional conductor, the compound is a with the IrDA communication manager of an externally installed communication device according to the present Invention permits, and connecting the externally installed communication device with this additional Head of the electronic device without significant modifications whose hardware and software a IrDA fulfilling added communication function will. This electronic device, simply additional with a Conductor is provided, needs no extra electricity as an electronic device does, requires significant modifications to the hardware and software, to allow that him an IrDA-fulfilling Communication function is added.

On externally installed communication device according to the present invention incorporates a level conversion driver and thus by simple connection of the externally installed communication device under Using therein IrDA communication with conductor the conductor which is provided in the existing electronic device is, the existing electronic device an IrDA communication function fulfilling added be without its Hardware and software can be modified. Within the externally installed communication device , the data transmission path, between the IrDA communication conductor and the level conversion driver runs, be bifurcated to additional with a Head to be separately connected to the IrDA communication manager. This eliminates the need, on the part of the existing electronic device an additional conductor provide in order to connect another electronic device to this can, which exchanges with this data, where it connected to the same conductor is, even when the communication device externally installed already connected to the conductors of the existing electronic device is.