FX929B Datasheet, PDF (35/48 Pages) CML Microcircuits – Flexible Operating Modes

4-Level FSK Modem Data Pump
FX929B
Figures 17a and 17b illustrate the host µC routines needed to receive a single Frame consisting of Symbol and
Frame Sync patterns, a Station ID block, a Header block, any number of Intermediate blocks and one Last
block. It is assumed that the Rx Interrupt Service Routine (Figure 17b) is called whenever the FX929B's IRQN
output line goes low.
Figure 17a Receive Frame Example Flowchart, Main Program
Note that the RESET command in Figure 17a and the practice of disabling the FX929B'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/929B/1