FX919B Datasheet, PDF (31/47 Pages) CML Microcircuits – Excellent Radio Fading Performance

4-Level FSK Modem Data Pump
FX919B
Figures 16a and 16b illustrate the host µC routines needed to send a single Frame consisting of Symbol and
Frame Sync patterns, a Header block, any number of Intermediate blocks and one Last block. It is assumed
that the Tx Interrupt Service Routine (Figure 15b) is called whenever the FX919B's IRQN output line goes low.
Figure 16a Transmit Frame Example Flowchart, Main Program
Note that the RESET command in Figure 16a and the practice of disabling the FX919B's IRQN output when not
needed are not essential but can eliminate problems during debugging and if errors occur in operation.
Note also that the CRC and TXIMP bits should be set appropriately whenever a byte is written to the Command
Register.
© 1997 Consumer Microcircuits Limited
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D/919B/1