Technical data

Analog Integrated Circuit Device Data
24 Freescale Semiconductor
34825
FUNCTIONAL DEVICE OPERATION
OPERATION AFTER IDENTIFICATION
Figure 16. Audio Accessory with Remote Control and Microphone
Figure 17. The Remote Control Key Pressing Timing
TEST ACCESSORY
The Test Accessories listed in Table 22 are special USB
cables and UART cables for test and R/D purpose. It has an
ID resistance to differentiate it from a regular USB cable or
UART cable. The test accessory has four ID resistance
values to distinguish the test cable type. The detection result
turns on or off the USB switches, UART switches, and the
power MOSFET automatically, as shown in the
Table 9.
MIC
VBUS
…...
R
1
R
2
R
3
R
N-1
R
N
HOLD
Audio_R
Audio_L
D+
D-
ID
GND
AUDIO
ACCESSORY
SEND/END
/
20 ms
Key Press
20 ms
T
KP
T
LKP
KP
INT
LKP
LKR
INT
ADC Time
Interrupt Register read
Interrupt Register read
Interrupt Register read
20 ms
Table 9. Switch Status vs. Test Cables
Accessory Type ADC Result Auto-ON Switches Power MOSFET
UART test cable type 1
01110 UART Switches OFF
UART test cable type 2
01111 UART Switches OFF
USB test cable type 1
10000 USB Switches ON
USB test cable type 2
10001 USB Switches ON
Other accessories
others No auto-on Switches No auto-on Switches