Specifications

Si2457/Si2434/Si2415
56 Rev. 0.91
Reset settings = 0x0000
Reset settings = 0x3240
U71 IO1
BitD15D14D13D12D11D10D9 D8 D7D6D5 D4 D3D2D1D0
Name COMP PRT
Type R/W R/W
Bit Name Function
15:5 Reserved Read returns zero.
4COMP0 = Disables compression (PCM mode).
1 = Enables linear compression.
3:1 Reserved Read returns zero.
0PRT0 = Disables PCM mode.
1 = Enables PCM mode.
U76 GEN1
Bit D15D14D13D12D11D10D9 D8 D7D6D5D4D3D2D1D0
Name OHSR[6:0] FACL DCL[2:0] ACL[4:0]
Type R/W R/W R/W
Bit Name Function
15:9 OHSR[6:0] Off-Hook Sample Rate (40 ms units).
Sets the sample rate for the off-hook intrusion algorithms (1 second default).
8FACLForce ACL.
0 = While off-hook, ACL is automatically updated with LVCS.
1 = While off-hook, ACL does not change from the value written to it while on-hook.
7:5 DCL[2:0] Differential Current Level (3 mA units).
Sets the differential level between ACL and LVCS that will trigger an off-hook PPD interrupt
(default = 2).
4:0 ACL[4:0] Absolute Current Level (3 mA units).
ACL represents the value of LVCS current when the ISOmodem® is off-hook and all parallel
phones are on-hook. If ACL = 0, it is ignored by the off-hook intrusion algorithm.The ISOmo-
dem will also write ACL with the contents of LVCS before an intrusion and before going on-
hook (default = 0).