Specifications

Si2457/34/15/04
Rev. 1.3 47
8. Pin Descriptions: Si2457/34/15/04 (24-Pin Option)
Pin # Pin Name Description
1CLKIN/XTALIClock Input/Crystal Oscillator Pin.
Provides support for parallel resonant AT cut crystals. A 4.9152 MHz or
32.768 kHz crystal or a 32.768 kHz or 4.9152 or 27 MHz clock on XTALI is
required.
2XTALOCrystal Oscillator Pin.
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 supply voltage to the Si2457/34/15/04.
6, 20 GND Ground.
Connects to the system digital ground.
7,19 VDA, VDB Regulator Voltage Reference.
Connects to an external capacitor and serves as the reference for the internal
voltage regulator.
8SS/RTS/D7 SPI Slave Select/Request to Send/Data Bit.
Active low slave select in SPI mode.
Active low request to send input used for flow control in UART mode. Bidirec-
tional 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
Si2457/34/15/04
(24-Pin Option)
CLKIN/XTALI
XTALO
CLKOUT/EECS/A0
FSYNC/D6
VD3.3
GND
VDA
SS/RTS/D7
MISO/RXD/RD
MOSI/TXD/WR
SCLK/CTS/CS
RESET
AOUT/INT
RI/D1
SDI/EESD/D2
VDB
VD3.3
ESC/D3
DCD/D4
GND
SDO/EECLK/D5
INT/DO
C1A
C2A