at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 670

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

37.2
Figure 37-1. Block Diagram
37.3
37.3.1
670
MCK
UDPCK
udp_int
external_resume
Block Diagram
Product Dependencies
AT91SAM9G20 Preliminary
Atmel Bridge
MCU
APB
I/O Lines
Bus
to
Access to the UDP is via the APB bus interface. Read and write to the data FIFO are done by
reading and writing 8-bit values to APB registers.
The UDP peripheral requires two clocks: one peripheral clock used by the Master Clock domain
(MCK) and a 48 MHz clock (UDPCK) used by the 12 MHz domain.
A USB 2.0 full-speed pad is embedded and controlled by the Serial Interface Engine (SIE).
The signal external_resume is optional. It allows the UDP peripheral to wake up once in system
mode. The host is then notified that the device asks for a resume. This optional feature must be
also negotiated with the host during the enumeration.
For further details on the USB Device hardware implementation, see the specific Product Prop-
erties document.
The USB physical transceiver is integrated into the product. The bidirectional differential signals
DP and DM are available from the product boundary.
One I/O line may be used by the application to check that VBUS is still available from the host.
Self-powered devices may use this entry to be notified that the host has been powered off. In
this case, the pullup on DP must be disabled in order to prevent feeding current to the host. The
application should disconnect the transceiver, then remove the pullup.
DP and DM are not controlled by any PIO controllers. The embedded USB physical transceiver
is controlled by the USB device peripheral.
U
e
n
e
a
e
s
c
r
I
t
r
f
W
a
p
p
e
Master Clock
Domain
r
r
USB Device
RAM
FIFO
Dual
Port
Recovered 12 MHz
Domain
W
a
p
p
e
r
r
Suspend/Resume Logic
12 MHz
Interface
Engine
Serial
SIE
txoen
eopn
txd
rxdm
rxd
rxdp
6384B–ATARM–15-Dec-08
Transceiver
Embedded
USB
DM
DP