VS1005g Datasheet
7
VS1005 GENERAL DESCRIPTION
Ethernet Controller
Ethernet Controller is an interface to 10base-t network. The interface uses digital signal levels
and external components are required to connect to ethernet. The core clock must be switched
to 60 MHz when ethernet peripheral is used.
The ethernet interface pins can also be used as general-purpose I/O.
USB
The USB peripheral handles USB 2.0 Full Speed and High Speed harware protocols. Low
speed communication is not supported, but is correctly ignored. The USBP pin has a software-
controllable 1.5kΩ pull-up.
A control endpoint (1 IN and 1 OUT) and upto 6 other endpoints (3 IN and 3 OUT) can be
used simultaneously. Bulk, interrupt, and isochronous transfer modes are selectable for each
endpoint. USB receive from USB host to device (OUT) uses a 2 KiB buffer, thus allowing very
high transfer speeds. USB transmit from device to USB host (IN) also uses a 2 KiB buffer and
allows all IN endpoints to be ready to transmit simultaneously. Double-buffering is also possible,
but not usually required.
The firmware uses the USB peripheral to implement both USB Mass Storage Device and USB
Audio Device. Which device is activated depends on the state of GPIO0_6 when the USB
connection is detected. If GPIO0_6 has a pull-up resistor, VS1005 appears as an USB Au-
dio Device. If GPIO0_6 has a pull-down resistor, VS1005 appears as an USB Mass Storage
Device.
7.2 Analog Section
The third regulator provides power for the analog section.
The analog section consists of digital to analog converters, an earphone driver and FM receiver.
This includes a buffered common voltage generator (CBUF, around 1.2 V) that can be used as
a virtual ground for headphones.
The regulator AVDD output pin must be connected to AVDD1 and AVDD2 pins with proper
bypass capacitors, because they are not connected internally. The AVDDRF pin is connected
to regulator CVDD pin with proper bypass capacitors or with external regulator from VHIGH.
The USB pins use the internal AVDD voltage, and the firmware configures AVDD to 3.6 V when
USB is attached.
AVDD voltage level can be monitored by software. Currently the firmware does not take advan-
tage of this feature.
CBUF contains a short-circuit protection. It disconnects the CBUF driver if pin is shorted to
ground. In practise this only happens with external power regulation, because there is a limit to
how much power the internal regulators can provide.
Version: 0.2, 2012-03-16
24
ETC [ ETC ]
