Controlling Protocol ......
“Write to Control Register”
– A/C 30
H
, followed by 1 byte of Command Data.
Setting
Audio Switch
See the Signal Switching diagram (Figure 3) and DBS 800
Document for application examples.
General Purpose Timer
Should be set up before interrupts are enabled, as a
General Reset command will set the timer period to
00
H
– 0ms (permanent interrupt).
Interrupt Enable Instructions
Status Bits 0, 1 and 2 are produced regardless of the state
of these settings.
Band Selection
Bits 2 and 3 set the required frequency range (see Figure
4, FX803 Frequencies).
Summing Switch
To break the FX803 drive to the FX806 PLMR Audio
Processor (see Figure 3, Signal Switching).
Interrupt Designation
Decoder Interrupts:
No Tone Timer and Rx Tone Measurement.
Transmitter Interrupt:
G/Purpose Timer Interrupt.
Control Bits
Transmitted First
Audio Switch
Enable
Disable
G/Purpose Timer Interrupt
Enable
Disable
Decoder Interrupts
Enable
Disable
Summing Switch
Enable
Disable
MSB
Bit 7
1
0
6
1
0
5
1
0
4
1
0
3
0
0
1
1
2
0
1
0
1
Band Selection
High Band
Mid Band
Extended Band
Do Not use this setting
Set to
“0”
Set to
“0”
1
0
0
0
Table 2 Control Register
“Read Status Register”
Reading
MSB
Bit 7
0
6
0
5
0
4
0
3
1
0
2
1
– A/C 31
H
, followed by 1 byte of Reply Data.
Status Bits
Received First
Set to
“0”
Set to
“0”
Set to
“0”
Set to
“0”
Logic Input Status
“1”
“0”
G/Purpose Timer Period
Expired
(IRQ generated if enabled)
(Table 2)
N
OTONE
Timer Period
Expired
(IRQ generated if enabled)
(Table 2)
Rx Tone Measurement
Complete
(Interrupt Generated)
Interrupt Requests (IRQ)
Interrupts on this device are available to draw the attention
of the
µController
to a change in the condition of the bit in
the Status Register. However Bits are set in the Status
Register irrespective of the setting of interrupt enable bits
(Table 2) and these changes may be recognized by
‘polling’ the register.
General Purpose Timer Period
Set
to a logic “1” when the timer period has expired.
Cleared
to a logic “0,”
i
By a read of the Status Register or,
ii New G/Purpose Timer information or,
iii General Reset Command
N
OTONE
Timer Period
Set
to a logic “1” when the timer period has expired.
Cleared
to a logic “0,”
i
By a read of the Status Register or,
ii New N
OTONE
Timer information or,
iii General Reset Command
Rx Tone Measurement
Set
to a logic “1” when the Rx Tone measurement is
complete.
Cleared
to a logic “0,”
i
By a read of the Status Register or,
ii General Reset Command
1
1
0
1
Table 3 Status Register
6
CMLMICRO [ CML MICROCIRCUITS ]
