Linux/AM4376: LPT port with GPIO

kesheng huang

Part Number: AM4376

Tool/software: Linux

Dear all:

We designed a POS motherboard using Am4376, and Kernel is Linux4.1.18. The main board receives the data sent by PC through the parallel port, and then sends it to the parallel port printer. We use GPIO to simulate parallel port transceiver, the following is our circuit design, I would like to ask whether such a design is reasonable, can meet the parallel port communication requirements? Now we can send data to the parallel port printer, but we can't receive the parallel data from PC. The main problem is that we cannot respond normally to STB (STROBE) interrupts。The J59 is connected the printer,the J60 is connected to PC.

Thanks!

over 8 years ago

0 kesheng huang over 8 years ago

Prodigy 150 points

0 Biser Gatchev-XID over 8 years ago in reply to kesheng huang

TI__Guru**** 393215 points

Hi,

Are you using GPIO or GPMC? Please clarify. What are the timings of your STB signal? Where is it connected?

0 kesheng huang over 8 years ago in reply to Biser Gatchev-XID

Prodigy 150 points

Hi，
We using the GPIO. The STB signal's timiings is 8us. It is connected to STROBE PIN of the PC LPT port .

0 Biser Gatchev-XID over 8 years ago in reply to kesheng huang

TI__Guru**** 393215 points

Is this actually the same issue that is described here: e2e.ti.com/.../603084

0 kesheng huang over 8 years ago in reply to Biser Gatchev-XID

Prodigy 150 points

Hi，

The B_STB signal is from the PC LPT port, used as the interrupt signal to received the LPT data. The B_STB interval is 8 microseconds, but we interrupt response delay (interrupt response programs only count interrupt times)more than 8 microseconds, why? Thanks.