Silicon Laboratories ISOMODEM Si2401, Manual

Page: 36 / 74

Si2401
36 Preliminary Rev. 0.9
S37 0x37 CDR Carrier detect return. Minimum length of time that a carrier must
return and be detected in order to be recognized after a carrier
loss is detected
(5/3 ms units).
0x20
S39 0x39 CDT Carrier detect timeout. Amount of time modem waits for carrier
detect before aborting call (1 second units).
0x3C
S3A 0x3A ATD Delay between going off-hook and answer tone generation when
in answer mode (53.33 ms units).
0x29
S3B 0x3B RP Minimum number of consecutive ring pulses per ring burst.
0x03
S3C 0x3C CIDG This is a bit mapped register.
*
0x01
S62 0x62 RC This is a bit mapped register.
*
0x41
S82 0x82 IST This is a bit mapped register.
*
0x08
SDB 0xDB LVS Line Voltage Status. Eight bit signed, 2s complement number
representing the tip-ring voltage. Each bit represents 1 volt.
Polarity of the voltage is represented by the MSB (sign bit).
0000_0000 = Measured voltage is < 3 V.
SDF 0xDF DGSR This is a bit mapped register.
*
0x0C
SE0 0xE0 CF1 This is a bit mapped register.
*
0x22
SE1 0xE1 GPIO1 This is a bit mapped register.
*
0x04
SE2 0xE2 GPIO2 This is a bit mapped register.
*
0x00
SE3 0xE3 GPD This is a bit mapped register.
*
0x00
SE4 0xE4 CF5 This is a bit mapped register.
*
0x00
SE5 0xE5 DADL (SE8 = 0x00) Write only definition. DSP register address lower
bits [7:0].
*
0x00
SE5 0xE5 DDL (SE8 = 0x01) Write only definition. DSP data word lower bits
[7:0].
*
0x00
SE5 0xE5 DSP1 (SE8 = 0x02) Read only definition. This is a bit mapped register.
1
0x00
SE5 0xE5 DSP2 (SE8 = 0x02) Write only definition. This is a bit mapped register.
1
0x00
SE6 0xE6 DADH (SE8 = 0x00) Write only definition. DSP register address upper
bits [15:8].
0x00
SE6 0xE6 DDH (SE8 = 0x01) Write only definition. DSP data word upper bits
[13:8]
0x00
SE6 0xE6 DSP3 (SE8 = 0x02) Write only definition. This is a bit mapped register.
1
0x00
SE8 0xE8 DSPR4 Set the mode to define E5 and E6 for low level DSP control.
0x00
Table 21. S-Register Summary (Continued)
“S”
Register
Register
Address
(hex)
Name Function Reset
*Note: These registers are explained in detail in the following section.