CMX865D2 CML Microcircuits, CMX865D2 Datasheet - Page 26

• Manufacturer Part Number: CMX865D2
• Description: FSK Modem and DTMF Codec
• Manufacturer: CML Microcircuits

FSK Modem and DTMF Codec
5.10.7 Status Register
Status Register: 16-bit read-only.
All the bits of this register (except b15-14) are cleared to 0 by a General Reset command, or when b7
(Reset) of the General Control Register is 1.
The meanings of the Status Register b12-0 depend on whether the receive circuitry is in Modem or Tones
Detect mode.
Notes: ** This column shows the corresponding IRQ Mask bits in the General Control Register. A 0-to-1
© 2005 CML Microsystems Plc
Bit:
The operation of the data demodulator and pattern detector circuits within the CMX865 does not
depend on the state of the Rx energy detect function.
Status Register bits:
transition on any of the Status Register b14-5 will cause the IRQ b15 to be set to 1 if the
corresponding IRQ Mask bit is 1. The IRQ bit is cleared by a read of the Status Register or a
General Reset command or by setting b7 or b8 of the General Control Register to 1.
IRQ
15
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
RD
14
1 when energy is detected in Rx
modem signal band
1 when ‘1010..’ pattern is detected
1 when continuous 0s detected
1 when continuous 1s detected
Set to 1 on Rx data ready. Cleared
by read from Rx Data Register
Set to 1 on Rx data overflow.
Cleared by read from Rx Data
Register
Set to 1 on Rx framing error
Set to 1 on even Rx parity
0
0
FSK frequency demodulator output
PF
13
12
Rx Modem modes
11
10
Cleared by write to Tx Data Register
Cleared by write to Tx Data Register
Programming Flag bit. See 5.10.8
C-BUS address $E6
Set to 1 on Tx data underflow.
Set to 1 on Tx data ready.
9
Set to 1 on Ring Detect
See below for uses of these bits
8
26
IRQ
7
1 when energy is detected in Call
Progress
programmable tones are detected
0
0
1 when 2100Hz answer tone or the
second
detected
1 when 2225Hz answer tone or the
first programmed tone is detected
1 when DTMF code is detected
0
Rx DTMF code b3, see table
Rx DTMF code b2
Rx DTMF code b1
Rx DTMF code b0
6
Rx Tones Detect modes
5
programmed
band
4
or
3
when
tone
2
both
1
is
** IRQ
Mask bit
0
CMX865
D/865/3
b5
b3
b3
b2
b1
b1
b1
b0
b0
b4
-
-
-
-
-