Micrel, Inc.
MIC2555
Pin Description
Pin Number
1
2
Type
O
I/O
Pin Name
RCV
SE0_VM_TX
Pin Description
Output from differential receiver.
= SE0 in USB DAT-SE0 mode
= VM in VP-VM mode.
= UART Transmit output when in UART Mode
See figures 1 and 2 on page 4
= DAT in USB DAT-SE0 mode.
= VP in VP-VM mode
= UART Receive input when in UART mode
See figures 1 and 2 on page 4
A Multi-mode pin controlling various functions in conjunction with
control register bits. A logic LOW on this pin gives the following
results:
= OE (Output Enable): Enables D+, D- as USB outputs.
= INT/ (Interrupt): Active LOW output when register bits ‘suspend’ and
‘oe_int_en’ both = 1.
Interrupt (bar). Open Drain Active LOW output. May be wire-ORed
with other interrupt signals.
= General purpose I/O. Open drain output.
= Alternate UART Receive input.
See figures 1 and 2 on page 4
= General purpose I/O. Open drain output.
= Alternate UART Transmit output.
See figures 1 and 2 on page 4
2
I C Clock
I
2
C Data
Sets Address bit A0 of I
2
C controller. This pin is a digital input and
must not be left floating.
System reset. Active LOW.
General purpose I/O. Open drain output.
System Digital ground.
Identification input. Monitors the ID pin of the USB connector and
indicates both the presence of a device and type (USB or not USB).
= USB D+ when in USB mode.
= UART Receive in UART mode.
= Right Speaker audio output in stereo mode.
= Microphone signal from Car Kit.
= USB D- when in USB mode.
= UART Transmit out in UART mode.
= Left Speaker audio output in stereo mode.
= Monaural audio output to Car Kit.
USB 5V power.
Internal 3.3V supply. Sets USB signal levels.
Positive lead for charge pump reservoir capacitor.
Positive lead for charge pump capacitor.
Positive voltage from battery. Supplies power to MIC2555 internal
circuitry and power for charge pump when driving VBUS.
Negative lead for charge pump capacitor.
Analog ground. Isolated Charge Pump ground.
Logic supply voltage. Used to set logic levels between MIC2555 and
System Controller / ASIC.
3
I/O
DAT_VP_RX
4
I/O
OE_INT/
5
6
O
I/O
INT/
GPIO_0_RX
7
8
9
10
11
12
13
14
I/O
I/O
I/O
I
I
I/O
I/O
I/O
GPIO_1_TX
SCL
SDA
ADR_0
RESET/
GPIO_2
GND_D
ID
15
I/O
D+
16
17
18
19
20
21
22
23
24
I/O
I/O
I/O
I
I
I
I
I
I
D-
VBUS
VTRM
CAP++
CAP+
VBAT
CAP-
GND_A
VDD_LGC
December 2006
3
M9999-121406
MICREL [ MICREL SEMICONDUCTOR ]
