John, Most of the time you don't want to acknowledge the interrupt if you have nothing to transmit. You want to *mask* it. Use the mask register. Later when you put something into the transmit queue, restore the normal mask value. The Tx interrupt will occur immediately, and you won't need special-case code in the send() routine. Just a thought that might work for your situation. Jeff "john_gma" <johnshaffer@...> on 09/10/2002 08:30:59 AM Please respond to 68300@yahoogroups.com To: 68300@yahoogroups.com cc: Subject: [68300] MC68376 QSM SCI Hello all, I am writing a serial driver for the QSM SCI. My question is in regards to the interrupt handling. There does not seem to be a separate ISR. How do I clear the interrupts? There are 2 flags I need to use, TDRE and TC. The book says that the flags are cleared by: 1. reading SCSR (OK, I do that) 2. Writing to TDR (I don't always want to do this) So, how do I acknowledge the interrupt without transmitting something? Can I write $0000 to SCSR? Thanks John --------------------------------------------------- To unsubscribe from this group, send an email to: 68300-unsubscribe@yahoogroups.com To learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Message
Re: [68300] MC68376 QSM SCI
2002-09-10 by jeffrey.tenney@gm.com