Specifications

Si2404
Rev. 0.91 61
Pin Descriptions: Si2404
Table 17. Si2404 Pin Descriptions
Pin # Pin Name Description
1 CLKIN/XTALI Clock Input/Crystal Oscillator Pin.
This pin provides support for parallel-resonant, AT cut crystals. XTALI also acts
as an input in the event that an external clock source is used in place of a crystal.
A 4.9152 MHz crystal or 4.9152/27 MHz clock is required.
2XTALOCrystal Oscillator Pin.
This pin provides support for parallel-resonant AT-cut crystals. XTALO serves as
the output of the crystal amplifier.
3 CLKOUT/EECS
/A0 Clock Output/EEPROM Chip Select/Address Bit 0.
Clock output in serial mode. Active low read/write enable for SPI EEPROM in
serial mode when pin 4 is pulled low during powerup. Address Enable in parallel
mode.
4 FSYNC
/D6 Frame Sync/Data Bit.
Frame Sync output to codec in serial mode. Bidirectional parallel bus data bit 6 in
parallel mode.
5, 21 VD3.3 Digital Supply Voltage.
Provides the 3.3 V digital supply voltage to the Si2404.
6, 20 GND Ground.
Connects to the system digital ground.
7,19 VDA, VDB Digital Rail.
Pin provides additional power supply voltage to the Si2404.
8RTS
/D7 Request-to-Send/Data Bit.
Request-to-send (for flow control) in serial mode. Bidirectional parallel bus data
bit 7 in parallel mode.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Si2404
CLKIN/XTALI
XTALO
CLKOUT/EECS/A0
FSYNC/D6
VD3.3
GND
VDA
RTS/D7
RXD/RD
TXD/WR
CTS/CS
RESET
AOUT/INT
RI/D1
SDI/EESD/D2
VDB
VD3.3
ESC/D3
DCD/D4
GND
SDO/EECLK/D5
INT/DO
C2A
C1A