VS1000
6
VS1000 FUNCTIONAL BLOCKS
6 VS1000 Functional Blocks
LEFT
RIGHT
CBUF
RCAP
VHIGH
PWRBTN
Reference
Stereo
Common
IOVDD
AVDD
Earphone
Driver
Voltage
Driver
Regulator
Regulator
AVDD1
AVDD2
AVDD3
Stereo
DAC
Voltage
Monitor
CVDD
Regulator
<1.6V
USBP
USPN
USB
reset
XCS/GPIO1[0]
SCLK/GPIO1[1]
SI/GPIO1[2]
Serial
X RAM
X ROM
Y RAM
Y ROM
I RAM
Data/
Control
Interface
SO/GPIO1[3]
VSDSP4
processor
RX/GPIO1[5]
TX/GPIO1[4]
UART
Clock
XTALO
XTALI
Data/
NAND
GPIO0[0...7]
Flash
Interface/
Control/
General IO
GPIO0[8...14]
I ROM
IOVDD1
IOVDD2
TEST
XRESET
Figure 2: VS1000 Block Diagram
6.1 Regulator Section
The VHIGH pin in the regulator section is used as a common main power supply for voltage
regulation. This input is connected to three internal regulators, which are activated when the
PWRBTN pin is set high for about one millisecond, so that AVDD starts to rise and reaches
about 1.5 V. After the PWRBTN has given this initial start current, the regulators reach their de-
fault voltages even if the PWRBTN is released. VHIGH must be sufficiently (about 0.3 V) above
the highest regulated power (normally AVDD) so that regulation can be properly performed.
The PWRBTN state can also be read by software, so it can be used as one of the user interface
buttons.
A power-on reset monitors the core voltage and asserts reset if CVDD drops below the CMON
level. It is also possible to force a reset by keeping PWRBTN pressed for longer than approx-
imately 5.6 seconds. A watchdog counter and the XRESET pin can also generate a reset for
the device.
Resets do not cause the regulators to shut down, but they restore the default regulator voltages.
After boot the firmware and user software can change the voltages.
Return to power-off is possible only with active software control (VSDSP writes the regulator
shutdown bit), or when VHIGH voltage is removed for a sufficiently long time. In the default
firmware player the power button has to be pressed for 2 seconds to make the software power-
down the system and turn the regulators off.
Version: 1.4, 2011-10-06
12
ETC [ ETC ]
