The size of the hardware FIFO changes from Dragonball 328 to EZ to VZ to SZ, and -- in the VZ -- is different depending on which UART you're using. For the most part, the size is 8 bytes, but is 64 for UART 2 on the VZ, and 32 on the SZ. You can read the Dragonball documentation for more details.
(However, scanning the source code for the serial drivers right now, I'm not sure you'll get reliable results from SrmSendCheck. First of all, its granularity is not to the byte level. The software can only probe to see if the FIFO is empty, half empty, or full. Second, by the time you get the results back, the state could have changed (that is, bytes could have drained). Finally, the FIFO is 32 or 64 bytes on some versions of the Dragonball, but the version of SrmSendCheck for those chips still appears to assume it's 8 bytes, as in older models.) -- Keith Rollin -- Palm OS Emulator engineer > -----Original Message----- > From: Stuart Nicholson [mailto:[EMAIL PROTECTED]] > Sent: Monday, January 20, 2003 2:14 PM > To: Palm Developer Forum > Subject: Palm Serial Port transmit FIFO size? > > > The New Serial Manager's SrmSendCheck() returns the number of > bytes in left in the transmit FIFO to send, however how many > bytes can I stuff into the FIFO before I can expect > SrmSend() to start failing? The documentation makes no > mention of the serial port's FIFO size (I assume this is a > standard somewhere?), nor do any of the supported Srm* > functions appear to allow me to query the hardware for this > information? > > Thanks for any help. > > (Yes I'm aware that SrmSend() returns the number of bytes > actually sent, however I'm dealing with a byte level > interface to a proprietry trunk radio stack and I'm dealing with > quite a low baud rate to radio hardware attached to the > Palm's cradle serial port). > -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
