A N 9 3
126
Rev. 1.4
U7A is a bit-mapped register. U7A resets to 0x0000. Bits 12, 10:8, and 5:3 are reserved.
Bit 7 (DOP) is used in a method to determine whether a phone line supports DTMF or only pulse dialing. See "6.10.
Pulse/Tone Dial Decision" on page 181 for details.
Bit 6 (ADD) attempts DTMF dial, then falls back to pulse dialing if unsuccessful. The first digit is dialed as DTMF. If
a dial tone is still present after two seconds, this suggests that the DTMF digit was not taken into account by the
central office. In that case, the ISOmodem redials the first digit and remaining digits as pulses. If a dial tone is not
present after two seconds, the ISOmodem assumes that the first DTMF digit was recognized and dials the
remaining digits as DTMF. However, in a typical PBX environment, where dialing a DTMF digit (typically 8 or 9) is
required to obtain an outside line, this method does not give any indication that the outside line can accept TDMF
dialing.
Bit 1 (HDLC) controls whether the normal asynchronous mode (default) is used or the transparent HDLC mode is
enabled. See "5.14. Legacy Synchronous DCE Mode/V.80 Synchronous Access Mode" on page 137 for more
details on these modes.
Bit 0 controls whether the normal ITU/Bellcore modem handshake (default) or a special fast-connect handshake is
used. Fast connect is typically used in specialized applications, such as point-of-sale terminals, where it is
important to connect and transfer a small amount of data rapidly (see Table 90).
Table 88. Monitor Mode Values
On-Hook Voltage Monitor Mode
Off-Hook Current Monitor Mode
00000 = No line connected.
00001 = Minimum line voltage (VMIN = 2.5 V ±0.5 V).
11111 = Maximum line voltage (87 V ±20%)
00000 = No loop current.
00001 = Minimum loop current.
11110 = Maximum loop current.
11111 = Overload (more than 60 mA in legacy TBR21
mode or more than 155 mA in other modes)
Table 89. U79 Bit Map
Bit
Name
Function
15:6
Reserved
Read returns zero.
5:0
LVCS
Line Voltage Current Sense.
When LLP (UAD[4] = 1 (default):
On-Hook = Voltage Monitor (2.75 V/bit).
Off-Hook = Loop Current Monitor (3 mA/bit).
When LLP (UAD[4] = 0:
On-Hook = Voltage Monitor (1.0 V/bit).
Off-Hook = Loop Current Monitor (1.1 mA/bit).
Table 90. U7A Bit Map
Bit
Name
Function
15
Reserved
Read returns zero.
14
CNSMS
Chinese EPOS SMS enable
1 = Enable
0 = Disable
*Note:
When HDLC or FAST is set, the \N0 (Wire mode) setting must be used.
Содержание Si2404
Страница 2: ...AN93 2 Rev 1 4 ...
Страница 27: ...AN93 Rev 1 4 27 Figure 7 Parallel Interface Read Timing Figure 8 Parallel Interface Write Timing ...
Страница 200: ...AN93 200 Rev 1 4 Figure 31 TAM Handset and Speakerphone Voice Paths ...
Страница 201: ...AN93 Rev 1 4 201 Figure 32 Si3000 Codec Gain and Signal Selection Options ...
Страница 290: ...AN93 290 Rev 1 4 Figure 57 256 Band Spectral Display Figure 58 2048 Band Spectral Display ...
Страница 305: ...AN93 Rev 1 4 305 Figure 76 Parallel or SPI Port Interrupt Service Flowchart ...