Maxim Integrated 73M1822/73M1922 Implementers Guide - Manual (Page 14)

73M1822/73M1922 Implementer’s Guide UG_1x22_052
14 Rev. 1.0
4.2 Off-Hook Request
The registers used in the off-hook request procedure are:
0x12 OFH ENDC ENAC ENSHL ENLVD ENFEL ENDT ENNOM
Write X/X/1/X 1/X/X/X X/X/0 or 1/1 X X 1/X/X/X X X/0/X/1
0x13 DCIV1 DCIV0 ILM RSVD PLDM OVDTH IDISPD IDISPD
Write VAL1[1:0] X X X X X X
0x14 TXBST DAA1 DAA0 Res RXBST RLPNH RXG1 RXG0
Write X X X X 0 X X X
0x15 Res DISNTR Res CIDM THEN ENUVD ENOVD ENOID
Write X X 0 0/X X/1 X X X
0x16 TXEN RXEN RLPNEN ATEN FSCTR3 FSCTR2 FSCTR1 FSCTR0
Write X/1 X/1 X X/1 VAL2[3:0] / X
The temporary variables defined in this procedure are:
VAL1 = System appropriate value for DCIV[1:0].
VAL2 = System appropriate value for FSCTR[3:0].
Begin
1. Set RXBST = 0 (write xxxx_0xxx to RG14).
2. Set CHPSEN = CIDM = 0 (write xx00_xxxx to RG15).
3. Set ENDC = ENFEL =1 (write x1xx_x1xx to RG12).
4. Set DCIV[1:0] = VAL1 (write VAL1[1:0]xx_xxxx to RG13).
5. Set FSCTR[3:0] = VAL2 (write xxxx_VAL2[3:0] to RG16).
6. Set THEN = 1 (write xxxx_1xxx to RG15).
7. Set ENNOM = 0 (write xxxx_xxx0 to RG12).
8. Set TXEN = RXEN = ATEN = 1 (write 11x1_xxxx to RG16).
9. Set OFH = 1. If using sieze state, set ENAC =0 else set ENAC =1. (write 1x0x_xxxx or 1x1x_xxxx to
RG12).
10. Wait until line settles (typical maximum is 350ms).
11. Set ENAC = ENNOM =1 (write xx1x_xxx1 to RG12).
End