CMX867D2 CML Microcircuits, CMX867D2 Datasheet - Page 22

• Manufacturer Part Number: CMX867D2
• Description: Low power V.22 modem
• Manufacturer: CML Microcircuits

Low Power V.22 Modem
2001 Consumer Microcircuits Limited
Tx Mode Register b8-7: Tx Guard tone (DPSK modes)
These 2 bits select the guard tone to be transmitted together with highband DPSK. Set
both bits to 0 in FSK modes.
Tx Mode Register b6-5: Tx Scrambler (DPSK modes)
These 2 bits control the operation of the Tx scrambler used in DPSK modes. Set both
bits to 0 in FSK modes.
Tx Mode Register b4-3: Tx Data Format (DPSK and FSK modes)
These two bits select Synchronous or Start-stop mode and the addition of a parity bit to
transmitted characters in Start-stop mode.
Tx Mode Register b2-0: Tx Data and Stop bits (DPSK and FSK: Start-Stop modes)
In Start-stop mode these three bits select the number of Tx data and stop bits.
Tx Mode Register b2-0: Tx Data source (DPSK and FSK: Synchronous mode)
In Synchronous mode (b4-3 = 11) these three bits select the source of the data fed to the Tx
FSK or DPSK scrambler and modulator.
b2
b2
1
1
1
1
0
0
0
0
1
0
0
0
b8
b6
b4
1
1
0
1
1
0
1
1
0
0
b1
b1
1
1
0
0
1
1
0
0
x
1
1
0
b7
b5
b3
1
0
x
1
0
x
1
0
1
0
b0
b0
1
0
1
0
1
0
1
0
x
1
0
x
Tx 550Hz guard tone
Tx 1800Hz guard tone
No Tx guard tone
Scrambler enabled, 64 ones detect circuit enabled (normal use)
Scrambler enabled, 64 ones detect circuit disabled
Scrambler disabled
Synchronous mode
Start-stop mode, no parity
Start-stop mode, even parity bit added to data bits
Start-stop mode, odd parity bit added to data bits
8 data bits, 2 stop bits
8 data bits, 1 stop bit
7 data bits, 2 stop bits
7 data bits, 1 stop bit
6 data bits, 2 stop bits
6 data bits, 1 stop bit
5 data bits, 2 stop bits
5 data bits, 1 stop bit
Data bytes from Tx Data Buffer
Continuous 1s
Continuous 0s
Continuous dibits ’00,11’ in 1200bps DPSK mode, continuous
alternating 1s and 0s in all other modes.
22
CMX867
D/867/2