Specifications

AN93
Rev. 0.9 85
3.3.28. U63 (DAAC2)
U63(DAAC2) is a bit-mapped register with bits 3:0 reserved and should be modified through a read-modify-write
operation.
Bits 15:8 (LCS) function as an 8-bit unsigned measure of off-hook loop current with a resolution of 1.1 mA/bit.
Bits 7:4 (ACT) set the ac termination the Si3010/Si3018/Si3019 presents to tip and ring. The ac impedance setting
is dictated by the certification requirements for the country in which the modem is used.
Table 50. U62
Bit Name Function
10 Full 2
This bit is available on Si3019 Rev E and later only, and is reserved on all other revisions
and DAA chips. When enabled, allows +6 dBm max into 600 Ω and guarantees >+3.2 dBm
in all 16 ac terminations of the Si3019E and later revisions.
0=Disable
1 = Enable.
7 Full 1
0=Disable
1 = Enable. +3.2 dBm maximum into 600 Ω.
Table 51. U63 Bit Map
Bit Name Function
15:8 LCS Off-hook loop current (1.1 mA/bit).
7:4 ACT AC Termination Select.
ACT AC Termination
0000 Real 600 Ω
0011 220 Ω + (820 Ω || 120 nF) and 220 Ω + (820 Ω || 115 nF)
0100 370 Ω + (620 Ω || 310 nF)
1111 Global complex impedance
3:0 Reserved Read returns 0011b.