mcs7720 MosChip, mcs7720 Datasheet - Page 4

• Manufacturer Part Number: mcs7720
• Description: Usb-1.1 To Dual Serial Ports
• Manufacturer: MosChip

Page 4
MCS7720
USB-1.1 to Dual Serial Ports
Pin Assignments
TSTMODE
TSTPLL
RESET
XTAL1
XTAL2
nDSR
nDSR
nRTS
Name
nCD
nCD
RX
RX
TX
DM
DP
B
B
A
B
A
B
B
A
Pin
10
12
15
18
19
20
26
27
28
29
3
4
6
7
9
Type
I/O
I/O
O
O
O
I
I
I
I
I
I
I
I
I
I
Crystal oscillator input or external clock input (6 MHz).
This signal input is used in conjunction with XTAL2 to form a feedback
circuit for the internal timing. Two external (10 pF) capacitors connected
from each side of the crystal to GND are required to form a crystal
oscillator
Crystal oscillator output. See XTAL1 description.
Test Mode (active low, internal pull-up) input.
When this pin is tied to GND, the internal PLL is bypassed and an
external 48 MHz clock is used as the reference clock.
Internal Test Mode (internal pull-up).
When this pin is tied to GND, the internal test mode is enabled.
Upstream USB port Differential data Minus (D-), analog.
Upstream USB port Differential data Plus (D+), analog.
System Reset (Active high).
Resets all internal registers, sequencers, and signals to a consistent
state. Connect to GND to enable the internal Power-On Reset circuit.
Carrier-Detect signal (B).
When low this indicates that the modem or data set has detected the
data carrier. nCD has no effect on the transmitter.
Data-Set-Ready signal (B).
When low, this indicates the modem or data set is ready to establish a
communication link.
Serial Data Input (B).
Request-To-Send signal (B).
It is set high (inactive) after a hardware reset or during internal loop-back
mode. When low, this indicates that the UART is ready to exchange
data. nRTS has no effect on the transmitter or receiver.
Carrier-Detect signal (A).
When low this indicates that the modem or data set has detected the
data carrier. nCD has no effect on the transmitter.
Data-Set-Ready signal (A).
When low, this indicates the modem or data set is ready to establish a
communication link.
Serial Data Output (B).
Serial Data Input (A).
Description
Rev.
1.1