As the description on the datasheet of SJA1000. The Transmit Interrupt is set to 1 whenever the Transmit Buffer State changes from "0-to-1". However, the Transmit Buffer State bit of State Register is "1" after reset in PeliCAN mode. After I enter the normal mode the Transmit Buffer State is still "1" all the time. The Transmit Interrupt is not generated. I'm not able to transmit message through Transmit Interrupt.
So I give a Transmit Request command first after I initial SJA1000 without the Transmit Interrupt previously. the Transmit Buffer State will be set to "0". Then the Transmit Buffer State is set to "1". And then the Transmit Interrupt is generated. So there are two problems about above all.
(1) Does the Transmit Interrupt is edge-triggered about Transmit Buffer State?
(2) So If I want to transmit the message through Transmit Interrupt. Must I set the Transmit Request command first after I initial SJA1000 without the transmit Interrupt previously to pull down the Transmit Buffer State. Then there will be a process of "0-to-1" change about Transmit Buffer State to generate the Transmit Interrupt.
Thank you !