Card does not return Status Word when data to retrieve exceeds 256 bytes

I'm working with a card in T=0 protocol:

I send a command to the Card that request a response with data.
The applet I use is expected to answer with data, potentially more than 256 bytes, so in the command Le is set to '00'
Card first answers with 61 XX where 'XX' is the count of bytes to read (from 1 to 256).
Then I retrieve the data by sending a GET RESPONSE command:

00 C0 00 00 XX

Expectation:

Regarding ISO7816-3, I expected the Card to respond with:

Procedure byte | Data | SW1 SW2

And if SW1 == 0x61, I would send:

00 C0 00 00 SW2

And so on, until eventually I get 90 00.

Reality:

However, this is what I actually have (TPDU level):

> Command
< 61 00

> 00 C0 00 00 00
< C0 (procedure byte)
< Data (256)
No Status Word, no procedure byte (timeout)

> 00 C0 00 00 00
< C0 (procedure byte)
< Data (256)
No Status Word, no procedure byte (timeout)

[...]

> 00 C0 00 00 00
< 61 39 (status word)

I have to repeatedly send GET RESPONSE with P3=00 (256), read the 256 bytes and got no Status Word until the Card warns me that there is actually less than 256 bytes to read.

I can't found the part of the specification that allows the card to "skip" the status word, or how to deal with answers longer than 256 bytes. Any pointer ?

Solution

I figured it out: it was a timing issue.

The card do have a Status Word to send, however my process between the read operations was too long so by the time I requested it, it was no longer available in the card.

I should have highlighted that I was developing the reader part myself.