Using the Driver
Start
Invoke
Echo_Initialize()
Invoke
Echo_Enable ()
Application initialization/
message creation
Yes
EnableDelay = 1?
No
Continue with application
Figure 7. Echo Driver Start Up
After invoking Echo_Enable(), there is a 2 ms start up delay while Echo is brought out of standby mode.
At this point, other application initialization may occur or messages for transmission may be constructed
to be sent after start up.
9.3
Transmitting Messages
There are two different formats for message transmission as detailed in section Section 3, “Message
Format.” The driver also provides support for double buffering of transmitted messages and explicit
control of the timing and number of Preamble/ID sequences. To support transmission in both formats and
allow explicit control of Preamble/ID repeats, there are a total of four services provided by the driver:
•
•
•
•
Echo_SendPreambleID—Send a preamble/ID sequence
Echo_SendData—Send the body of a message
Echo_SendMessage—Send an entire message telegram
Echo_SendIDRepeat—Send a message in ID repeat format
Software Drivers for MC33696, Rev. 1
Freescale Semiconductor
13
FREESCALE [ Freescale ]
