............... Document #: SP-AP-0757 (Rev. 0.2) Page 2 of 13
Pin Definitions
Serial Data Interface
To enhance the flexibility and function of the clock synthesizer,
a two-signal serial interface is provided. Through the Serial
Data Interface, various device functions, such as individual
clock output buffers are individually enabled or disabled. The
registers associated with the Serial Data Interface initialize to
their default setting at power-up. The use of this interface is
optional. Clock device register changes are normally made at
system initialization, if any are required. The interface cannot
be used during system operation for power management
functions.
Data Protocol
The clock driver serial protocol accepts byte write, byte read,
block write, and block read operations from the controller. For
block write/read operation, access the bytes in sequential
order from lowest to highest (most significant bit first) with the
ability to stop after any complete byte is transferred. For byte
write and byte read operations, the system controller can
access individually indexed bytes. The offset of the indexed
byte is encoded in the command code described in Table 1.
The block write and block read protocol is outlined in Table 2
while Table 3 outlines byte write and byte read protocol. The
slave receiver address is 11010010 (D2h).
Pin No.
Name Type Description
1 VDD PWR 3.3V Power supply
2 SDATA I/O SMBus compatible SDATA.
3 SCLK I SMBus compatible SCLOCK.
4 VDD PWR 3.3V power supply
5 VSS GND Ground
6 VDD PWR 3.3V power supply
7 VSS GND Ground
8 SRC1 O, DIF 100 MHz Differential serial reference clocks.
9 SRC1# O, DIF 100 MHz Differential serial reference clocks.
10 VSS GND Ground
11 SRC2 O, DIF 100 MHz Differential serial reference clocks.
12 SRC2# O, DIF 100 MHz Differential serial reference clocks.
13 VDD PWR 3.3V power supply
14 VDD PWR 3.3V power supply
15 SRC3# O, DIF 100 MHz Differential serial reference clocks.
16 SRC3 O, DIF 100 MHz Differential serial reference clocks.
17 VSS GND Ground
18 SRC4# O, DIF 100 MHz Differential serial reference clocks.
19 SRC4 O, DIF 100 MHz Differential serial reference clocks.
20 VDD PWR 3.3V power supply
21 SSON I 3.3V LVTTL input for enabling spread spectrum clock
0 = Disable, 1 = Enable (-0.5% SS)
External 10K ohm pull-up or pull-down resistor required
22 VSS GND Ground
23 XOUT O, SE 14.318 MHz Crystal output.
24 XIN I 14.318 MHz Crystal input.
