Chapter 5

I2C Error Messages

 

 

The error messages are only visible during error conditions. The error

 

 

messages are located just above the RESET button in the main panel. The first

 

 

message to appear will be above the second message. For example, if an ACK

 

 

error occurs first then it is displayed first and it is only displayed once. The

 

 

software continues to send data to the device even with ACK and WAIT errors.

 

 

But it no longer looks for ACK or WAIT errors, therefore the response from the

 

 

device can be undetermined.

 

 

 

No.

Error Message

Cause

 

 

 

1

ACK error

The AIC23/DAC23 is not sending an acknowledge command back to the host processor.

 

 

This is referred to as an ACK in I2C terminology. The software does not terminate the

 

 

transactions.

 

 

 

 

 

Pin 1 (SDA) or pin 14 (SCL) on the parallel cable is not allowing the I2C commands to

 

 

reach the EVM.

 

 

 

 

 

Pin 15 on the parallel cable is not allowing the ACK command to return back to the host.

 

 

 

 

 

The LPT port is not connected and configured for EPP or bidirectional mode (PS-2 in

 

 

some cases).

 

 

 

 

 

The actual LPT port connected does not match the LPT port selected in the *.dat file.

 

 

 

 

 

LPT1 is the default for the LPT port, if it is not explicitly defined in the file. The

 

 

hexadecimal addresses for the ports defined in the software are LPT1 = 0x378,

 

 

LPT2 = 0x278, and LPT3 = 0x3BC.

 

 

 

 

 

The actual LPT port base address selected does not match any of the following

 

 

hexadecimal addresses:

 

 

LPT1 = 0x378

 

 

LPT2 = 0x278

 

 

LPT3 = 0x3BC

 

 

 

2

WAIT error

The AIC23/DAC23 is holding the SCL line low and not releasing it for the host processor.

 

 

This is referred to as waiting the bus in I2C terminology. The AIC23/DAC23 software

 

 

does not terminate the transactions.

 

 

 

 

 

Pin 1 (SDA) or pin 14 (SCL) on the parallel cable is not allowing the I2C commands to

 

 

reach the EVM.

 

 

 

 

 

Pin 10 on the parallel cable is not allowing the host to read a high SCL. Therefore a WAIT

 

 

is assumed.

 

 

 

5-1

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Texas Instruments TLV320AIC23, TLV320DAC23 manual I2C Error Messages, Device can be undetermined