Hi,

I am going to use the circuit shown in below link for programming 24Cxx series EEPROM device. I have few queries regarding the analysis of the circuit.

Circuit Link : http://www.lancos.com/e2p/easyI2Cbus.gif

Queries :

1. The D0 (Pin 2) and D1 (Pin 3) of Parallel port are connected to SDA and SCL of EEPROM through Transistor. I understand that this connection is done to provide open collector driver. But whether this results in inversion of DATA and CLOCK signals?

2. The I2C Data line is bi-directional. When DATA is Input to LPT (driven by EEPROM), how the data transmission happens in spite of the Transistor connection?

3. Why SDA and SCL are connected to Pin 12 (PAPER_OUT) and 13 (SELECT) of Parallel port?


Please clarify these queries before we start assembling the circuit.

Regards,
Vijetha



Edited 1 time(s). Last edit at 04/07/2015 09:01AM by vijethahn.

Hi Vijetha,

here are the answers for your questions:

1. The two transistors connected to LPT connector on pin 2 and pin 3 are used only by the "data" transmission from pc to the i2c device connected via easyI2Cbus interface. And yes, they are both inverted.

2. & 3. For receiving data (from i2c device to PC) are only used LPT pin 12 and pin 13. The transistors are in this direction unused.

Every communication is fully controlled by software - PonyProg2000. The output data is "created" by generating voltage levels (log.0 = 0V and log.1 = 5V) for driving external transistors (pin 2, pin 3). Reading the input "data" (voltage levels at LPT pins 12 and 13) at the time defined by the communication protocol is controlled by software as well. So if you choose in PonyProg2000 on the interface setup dialog the correct interface type, the software automatically makes needed settings (e.g. inverted/not inverted signals) internally.

Communication ports COM and LPT are used by the PonyProg2000 ONLY as a PC input / output interfaces with direct access to their pins. There is no standard data flow, so in this case is the meaning of pin descriptions more or less irrelevant.

Yours sincerely
sonix

vijethahn Wrote:
-------------------------------------------------------
> Hi,
>
> I am going to use the circuit shown in below link
> for programming 24Cxx series EEPROM device. I have
> few queries regarding the analysis of the
> circuit.
>
> Circuit Link :
> http://www.lancos.com/e2p/easyI2Cbus.gif
>
> Queries :
>
> 1. The D0 (Pin 2) and D1 (Pin 3) of Parallel port
> are connected to SDA and SCL of EEPROM through
> Transistor. I understand that this connection is
> done to provide open collector driver. But whether
> this results in inversion of DATA and CLOCK
> signals?
>
> 2. The I2C Data line is bi-directional. When DATA
> is Input to LPT (driven by EEPROM), how the data
> transmission happens in spite of the Transistor
> connection?
>
> 3. Why SDA and SCL are connected to Pin 12
> (PAPER_OUT) and 13 (SELECT) of Parallel port?
>
>
> Please clarify these queries before we start
> assembling the circuit.
>
> Regards,
> Vijetha

Thank Ypu for the reply. Your answers clarified my questons on hardware analysis. I am building the circuit. Will come come back if I face any issue in programming.

Regards,
Vijetha

Dear sonix,

I am going to use the circuit shown in below link for programming 93LCxx series EEPROM device.

http://www.lancos.com/e2p/si-prog-v2_2.pdf

So I kindly want to ask you to analysis this circuit operation (Base Board + Microwire 93xx adapter).

tnx.



Edited 1 time(s). Last edit at 05/31/2015 10:22AM by ebrahim.

Dear Ebrahim,

the eeprom range 93LCxx is supported by PonyProg2000 and hw interface Siprog together with microwire eeprom adapter. For details about programming see PonyProg's built-in help or online documentation under section "3.1.3 Microwire (3-wire) eeprom adapter" ( http://www.lancos.com/e2p/ponyprog2000.html#s3.1.3 )

Yours sincerely
sonix


ebrahim Wrote:
-------------------------------------------------------
> Dear sonix,
>
> I am going to use the circuit shown in below link
> for programming 93LCxx series EEPROM device.
>
> http://www.lancos.com/e2p/si-prog-v2_2.pdf
>
> So I kindly want to ask you to analysis this
> circuit operation (Base Board + Microwire 93xx
> adapter).
>
> tnx.

Dear sonix

Thank you for your prompt reply.
I would like to know how the base board circuit works (from electronic point of view). As I read in technical documents, in DB9 serial port, pin 2 and 3 are TXD and RXD and they are used for send and receive data. But in base board circuit they have different function. In this circuit, pin 2 has not connected to any where, and pin 3 has connected to pin 1 of 93LCxx IC, which is CS pin (Chip Select).
I would like to know your analysis about this circuit operation.

Kind regards,



Edited 1 time(s). Last edit at 06/01/2015 12:38PM by ebrahim.

Hi Ebrahim,

I have created the new topic describing electrical functionality for SI Prog hw interface that PonyProg uses for communication to the serial devices.

http://ponyprog.sourceforge.net/phorum/read.php?2,2554

Yours sincerely
sonix


ebrahim Wrote:
-------------------------------------------------------
> Dear sonix
>
> Thank you for your prompt reply.
> I would like to know how the base board circuit
> works (from electronic point of view). As I read
> in technical documents, in DB9 serial port, pin 2
> and 3 are TXD and RXD and they are used for send
> and receive data. But in base board circuit they
> have different function. In this circuit, pin 2
> has not connected to any where, and pin 3 has
> connected to pin 1 of 93LCxx IC, which is CS pin
> (Chip Select).
> I would like to know your analysis about this
> circuit operation.
>
> Kind regards,

Thank you sonix.