User's Manual

UniStone
Basic Operating Information
Product Overview 14 T3130-8XV10PO5-7600, 2007-01-31
2 Basic Operating Information
2.1 Power Supply
BlueMoon UniCellular is supplied from a single supply voltage VSUPPLY. This supply
voltage must always be present. The Bluemoon UniCellular chip is supplied from an
internally generated 2.5 V supply voltage. This voltage can be accessed from the VREG
pin. This voltage may not be used for supplying other components in the host system but
can be used for referencing the host interfaces.
The PCM interface and the UART interface are supplied with dedicated, independent,
reference levels via the VDDPCM and VDDUART pins. All other digital I/O pins are
supplied internally by either 2.5 V (Internal2) or 1.5 V(Internal1). Section 1.4 provides a
mapping between pins and supply voltages.
The I/O power domains (VDDPCM and VDDUART) are completely separated from the
other power domains and can stay present also in low power modes.
2.2 Clocking
BlueMoon UniCellular has one clock input CLK32 that is optional. If used this 32.768 kHz
clock must always be present to assist BlueMoon UniCellular to keep the time in low
power modes.
The low power clock can be generated internally by the crystal oscillator and/or the low
power oscillator or provided externally.