Silicon Laboratories SI2493/57/34/15/04, SI2494/39 manual Overview, Handset Configuration

AN93

	Table 119. Initialization Sequence (Continued)
			Configure Si3000 Register 7:
AT:U72,075E		OK	0 dB RX PGA gain
			Enable SPKRL
			Mute SPKRR
		OK	Configure Si3000 Register 9:
AT:U72,0900			0 dB Line Out attenuation
			0 dB Speaker output attenuation
AT:U0B1,0		OK	Disable Si3000-to-DAA transmit gain
			path. This ensures codec tones are not
			sent to the FDV and DTMF.
			Disable DAA-to-Si3000 receive gain
AT:U0B5,0		OK	path. This ensures line events such as
			CID and ring tone are not heard via the
			codec.
AT:U199&FFF7		OK	Enable speaker for local ring tone/alert
			tones.

7.5. Handset

7.5.1. Overview

This mode uses the voice pass-through connection to route SSI data between the Si3000 and the DAA. The modem remains in AT command mode and provides V.253 event notifications. The host controller is responsible for detecting the status of the handset position. The following sections provides detailed examples of originating and answering a voice call with the handset.

7.5.2. Handset Configuration

Table 120 contains the initial configuration that is used by all dialing use cases. The sequence is also sent for the answer case. The user will have been notified of the incoming call through a local +VTS ring tone and a raised handset event would prompt the Handset Configuration sequence to answer the call. The UB1, UB5, UB6, and Si3000 register configuration vary with the customer’s production hardware. The UB5 register serves as the general volume control in this mode.

196 Rev. 1.3