MAS 3504D
4.2.1. Pin Descriptions
4.2.1.3. Control Lines
4.2.1.1. Power Supply Pins
I2CC
I2CD
SCL
SDA
IN/OUT
IN/OUT
Connection of all power supply pins is mandatory for
the function of the MAS 3504D.
Standard I2C control lines. Normally there are Pull-up-
resistors tied from each line to VDD.
VDD
VSS
SUPPLY
SUPPLY
4.2.1.4. Parallel Interface Lines
4.2.1.4.1. PIO Handshake Lines
The VDD/VSS pair is internally connected with all digi-
tal modules of the MAS 3504D.
XVDD
XVSS
SUPPLY
SUPPLY
’PIO handshake lines’ are used in operation mode.
PIO-DMA mode is used in input mode and µP mode in
output mode.
The XVDD/XVSS pins are internally connected with
the pin output buffers.
PCS
IN
AVDD
AVSS
SUPPLY
SUPPLY
The ’PIO chip select’ is driven from microcontroller to
activate data output from MAS 3504D to the bus. Data
is output to the bus on the falling edge of PCS and is
removed on the rising edge of PCS.
The AVDD/AVSS pair is connected internally with the
analog blocks of the MAS 3504D, i.e. clock synthe-
sizer and supply voltage supervision circuits.
PR
IN
The ’PIO request’ must be set to ‘1’ to validate data
4.2.1.2. DC/DC Converter Pins
output from MAS 3504D.
DCEN
IN
RTR
OUT
The DCEN input signal enables the DC/DC converter
operation.
‘Ready to read’ is driven from the MAS 3504D in PIO/
DMA input mode.
DCSG
SUPPLY
RTW
OUT
The ‘DC converter Signal Ground’ pin is used as a
basepoint for the internal switching transistor of the
DC/DC converter. It must always be connected to
ground.
‘Ready to write’ is driven from MAS 3504D to indicate
that data is available in PIO output mode.
EOD
OUT
DCSO
OUT
‘End of DMA’ is supported by the built-in firmware in
PIO-DMA input mode.
DCSO is an open drain output and should be con-
nected with external circuitry (inductor/diode) to start
the DC/DC converter. When the DC/DC converter is
not used, it has to be connected to VSS.
4.2.1.4.2. PIO Data Lines
PI19...PI12
PARALLEL DATA
OUT/IN
VSENS
IN
These pins are used to send or receive compressed
data.
The VSENS pin is the input for the DC/DC converter
feedback loop. It must be connected directly with the
Schottky diode and the capacitor as shown in Fig. 2–1
on page 7.
When the DC/DC converter is not used, it has to be
connected to VDD.
Micronas
25
MICRONAS [ MICRONAS ]
