Datasheet

Analog Integrated Circuit Device Data
Freescale Semiconductor 98
MC34708
Functional Block Description
Figure 28. Operation of the Headset with Remote Control and Microphone
Figure 29. Remote Control Key Press Timing
The ID detection circuit continues to be ON for detaching detection in the Active mode, and samples the ID line every interval
programmed by the device wake-up bits in the USB Timing register. When the ID_FLOAT rising edge is detected, the Detach bit
in the USB Interrupt Sense register is set to inform the host the accessory is detached. The MC34708 then enters Standby mode.
VBUS
ID
D+
D-
GND
Baseband
SHLD
ADC
ID Det
AUDIO ACCESSORY
MIC
SPKR_R
SPKR_L
VBUS
DP
DM
ID
GND

20ms
Key
Press
20ms
T
KP
T
LKP
Error
INT
KP
INT
LK P
LKR
INT
ADC
Time
Button Register read
KP
Interrupt Status 0 Register KP bit wr itten to a one
Interr upt Status 0 Register KP bit written to a one
Interrupt Status 0 Register
LKP bit written to a one
Interr upt St atus 0 Register
LKR bit written to a one