MT90812 Mitel Networks Corporation, MT90812 Datasheet - Page 62

• Manufacturer Part Number: MT90812
• Description: Integrated Digital Switch (IDX)
• Manufacturer: Mitel Networks Corporation

MT90812
22.7
The Ringer and FSK Control register (RFC) controls the Ringing Source and FSK Transmitter.
The Ringer and FSK control register is configured as follows:
The Ringer and FSK Control Register (RFC) is used to select the type of interrupt, the idle state, the ‘mark’ and
‘space’ frequency standard, and to turn on or off the transmitter. The idle state of continuous ‘mark’ or
continuous ‘space’ or a ‘channel seizure’ signal of alternating ones and zero’s can be selected. Changing S1,
S0 bits will change the idle state on the next bit boundary. At 1200 baud, one bit corresponds to 6
58
Read/Write Address is: 006
Reset Value is: 00
6-5
2-3
Bit
7
4
1
0
Ringer and FSK Control Register (RFC)
S1, S0
Name
F1,F0
FMS
FEN
FIS
RE
H
Ringer Enable bit.
Selects the frequency of the square wave output of the Ringing Generator. The
Ringer outputs are the R+ and R- pins.
00 = 16 Hz square wave
01 = 20 Hz square wave
10 = 25 Hz square wave
11 = 50 Hz square wave
FSK Interrupt Select. 0 = interrupt generated when the TX FIFO is empty.
1= interrupt generated at the end of transmission.
00 = Idle state is continuous ‘space’ (logic zero).
01 = Idle state is continuous ‘mark’ (logic one).
10 = Turn on channel seizure signal.
11 = unused.
FEN=0 disables the FSK Transmitter and clears the FSK FIFO. Writing to FSK FIFO
while FEN=0 will have no effect.
When 1 the FSK transmitter is enabled, and the FSK transmit memory can be written to.
When the memory is empty, the idle state set by bits S1-0, is output until the transmit
memory is reloaded or the transmitter is turned off.
0 = Mark and Space frequencies of 1200 Hz and 2200 Hz corresponding to Bell 202
standard.
1 = Mark and Space frequencies of 1300 Hz and 2100 Hz corresponding to CCITT V.23
standard.
H
RE
7
F1
6
F0
5
FIS
4
S1
3
S0
2
Description
FEN
1
FMS
0
Advance Information
2
/
3
frames.