Analog Integrated Circuit Device Data
Freescale Semiconductor
109
PC34708
Functional Block Requirements and Behaviors
Mini/Micro USB Interface Description and Application Information
1. Recognized and supported. The following accessories are identified and configured automatically: USB port, dedicated
charger, USB charger, A/V charger, 5-wire type 1 and type 2 chargers, UART, Audio Type 1 cable, TTY accessory, USB
jig cables, and UART jig cables.
2. Recognized but not supported. The following accessories can be identified but are not supported by the PC34708 PMIC:
A/V cables, Phone-Powered Devices, and Audio Type 2 cables.
3. Not recognized accessories. All accessories that are not recognized are identified as unknown accessories.
Figure 23. Identification Flow State Diagram
7.10.4 Id Identification
A comparator monitors the ID pin impedance to ground. When a resistor less than 1.0 M
Ω is connected between the ID line and
the ground, the ID_FLOATS bit in the Interrupt Sense 0 register will be set to 0. When the resistor is removed, the ID_FLOATS
bit will be set to 1. A falling edge of this bit starts the identification flow, and a rising edge starts the detachment detection flow.
The ID_DET_END signal is used to indicate the end of the identification.
After the ID_FLOATS bit is set to 0, the identification flow is started, and an ADC_EN signal is set to enable an ADC conversion.
A 5-bit ID ADC is used to measure the ID resistance. The ADC is also used to identify what button is pressed in a cord remote
control when the attached accessory is an Audio Type 1 cable.
When the conversion completes, an ADC_STATUS bit is set and the ADC result value is sent to the ADC Manual SW/Result
register. The ADC_EN signal is cleared automatically after the conversion finishes.
If the ID resistance is below 2.0 k
Ω, the ADC Result is set to 00000. If the ID line is floating, the ADC Result is set to 11111.
VBUS_DET?
Detection
Delay
USB host
USB-OTG
RID = USB
jig w/ Boot?
USB jig
cable w/
boot option
Unknown
ID_FLOAT?
RID < 100Π?
RID = 75Π?
Video
cable
Start ADC to
measure RID
RID = UART
jig w/ boot?
RID = Audio
Type 1 ?
Audio
Type 1
RID =
102k
Π?
Phone
Powered
Device
Yes
No
Yes
No
RID = Video
cable?
No
Yes
RID = USB
jig w/o Boot?
USB jig
cable w/o
boot option
Yes
No
UART jig
cable w/
boot option
RID = UART
jig w/o boot?
Yes
No
UART jig
cable w/o
boot option
RID = TTY
Converter?
TTY
Converter
Yes
RID = UART
Cable?
UART
Cable
Yes
No
DP
0.6V
DM < 0.4V?
Yes
No
DM > 0.8V
No
Yes
No
ID_FLOAT?
Yes
ID_FLOAT?
No
Yes
A/V_CHG = 1
ID_DET_EN
D?
Yes
No
Standby
Active
(Identification
Flow)
RID = Audio
Type2
Cable?
Audio
Type2
Cable
Yes
Dedicated
Charger
RID =
440k
Π?
RID =
200k
Π?
5-Wire
Charger
No
Yes
No
ID_FLOAT
ID_DET_EN
D?
Yes
No
Yes DM 0.6V
DP < 0.4V?
No
Yes
USB
Charger
ADC = 00000
No
RID = remote
key?
No
Yes
Stuck Key
Process
ID_DET_EN
D?
No
Yes
Video cable?
Yes
No
Reset