Silicon Laboratories SI2493/57/34/15/04, SI2494/39 manual U19E, U199 Bit Definitions

AN93

Table 115. U199 and U19E Register Bit Maps

Reg	Name	Bits	Bit8	Bit7	Bit6	Bits	Bit 3	Bit 2	Bit 1	Bit 0
		15-9				4-5
U199	VPCTRL		SSP_LOCTALK	SSP_PTT	SSP_FLAG		MMUTE	SPCAL	SMUTE
U19E	AECREF		SPKREF			MICREF

The SMUTE bit (U199 [1]) mutes the speaker output audio path. The bit should be cleared for normal speakerphone operation. For recording during hands-free TAM, the bit should be set to mute the speaker output.

The MMUTE bit (U199 [3]) mutes the microphone input audio path. The bit should be cleared for the normal speakerphone operation. For message review during hands-free TAM, the bit should be set to mute the microphone.

Bit SPCAL (U199 [2]) in U199 must be set for speakerphone’s calibration and cleared for normal speakerphone operation.

Bit fields SPKREF and MICREF in U19E contain the speakerphone’s speaker and microphone levels during speakerphone calibration.

			Table 116. U199 Bit Definitions
Bit	Name	Function
8	SSP_LOCTALK	1	= Local talker enabled
		0	= Remote talker enabled
		Toggled by <DLE><0x27>
7	SSP_PTT	1	= Manually switch between near/far talker (push-to-talk mode)
		0	= Automatically switch based on signal levels
		Toggled by <DLE><0x26>
6	SSP_FLAG	1	= Enable SSP mode
		0	= Disable SSP mode
		Toggled by <DLE><0x25>
3	MMUTE	1	= Mute speaker of speakerphone or handset
		0	= Unmute speaker
2	SPCAL	1	= AEC speaker / microphone calibration
		0	= Normal mode
1	SMUTE	1	= Mute local talker
		0	= Unmute local talker

186 Rev. 1.3