CTCSS/DCS/SELCALL Processor

FX828

© 2009 CML Microsystems Plc

22

D/828/4

1.6.6

General Purpose Timer (GPT)

This may be used in conjunction with the CTCSS/Selcall decoder to form part of the decode algorithm or

as a timer for any other purpose. It has an 8-bit value in the GENERAL PURPOSE TIMER Register ($8B)

set in units of 1msec, an IRQ FLAG in Bit 6 of the IRQ FLAG Register ($8F) and an IRQ MASK in Bit 6 of

the IRQ MASK Register ($8E).

1.6.7

Full Duplex Modes

The only functions that must operate as half duplex are:

DCS Tx

or DCS Rx

DCS Tx

or CTCSS Tx

CTCSS decode or SELCALL decode

All other functions are totally independent and therefore a full duplex CTCSS or full duplex SELCALL

along with many other combinations are possible.