rs232 fprintf pacing question

[j@qmail.com]

Does anyone know how ccs paces rs232 output (with and without USART)? For example, suppose I fprintf ten characters to a stream. Do I get control back immediately or do I have to wait for the characters to be transmitted?

If I get control back immediately, what happens if I send another ten characters?

(It seems to me that there should be a "ready" bit somewhere to test but I haven't found it in the docs I have.)

Tnx,
Jay
___________________________
This message was ported from CCS's old forum
Original Post ID: 13633

[PCM programmer]

:=Does anyone know how ccs paces rs232 output (with and without USART)? For example, suppose I fprintf ten characters to a stream. Do I get control back immediately or do I have to wait for the characters to be transmitted?
:=
:=If I get control back immediately, what happens if I send another ten characters?
:=
:=(It seems to me that there should be a "ready" bit somewhere to test but I haven't found it in the docs I have.)
:=
------------------------------------------------------------

You're asking if fprintf() has a software transmit fifo.
It doesn't. So, yes, you'll have to wait until most of
the characters are transmitted.

If you want a transmit buffer, you have to add the code for it.
CCS has an example file for this, called EX_STISR.C.
It's in this folder: c:\Program Files\Picc\Examples

The same thing is true for a receive fifo. You have to code it.
See EX_SISR.C for an example. It's in the same folder.
___________________________
This message was ported from CCS's old forum
Original Post ID: 13634

[j@qmail.com]

:=You're asking if fprintf() has a software transmit fifo.
:=It doesn't. So, yes, you'll have to wait until most of
:=the characters are transmitted.

Thanks,
Jay
___________________________
This message was ported from CCS's old forum
Original Post ID: 13645