Hello everyone, On the QSM module of the MC68300 and MC68HC16 families, there is the TDRE bit and the TC bit. The TDRE bit tells you that another byte can be loaded into the "transmit data buffer" which is different from the "transmit shifter". The TC bit tells you that the "transmit shifter" is empty and that there is no byte waiting in the "transmit data buffer". On the QSPI, there is a somewhat similar situation. The SPIF flag tells you that a new byte can be written to the SPI data buffer. It does not necessarily mean that the "shifter" is empty as well. The only way to tell that the QSPI shifter is empty is to monitor the SPE bit which will "self clear" when the transmission is finished. Regards, Charlie -----Original Message----- From: Bill Hartmann [mailto:billhart@...] Sent: Wednesday, June 12, 2002 6:47 AM To: 68300@yahoogroups.com Subject: RE: [68300] 68376: RS485 half duplex setup Also you can send a dummy character at the end of the data string. Then after the last TDRE you can turn the system around. We have been doing that for years with a 6809/6850 and 6801 radio systems. On Mon, 10 Jun 2002 17:05:07 -0400, Godiska, Jim wrote: >Well, I was hoping to avoid a timer. But thanks, I like the CTM one-shot >idea. > -------------------------------------------------------------------------------- Bill Hartmann Lake Tapawingo, MO (near Kansas City) billhart@... --------------------------------------------------- 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 <http://www.motorola.com/mcu> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> .
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RE: [68300] 68376: RS485 half duplex setup
2002-06-12 by Melear Charles-rdph40